nucleoside diphosphate-linked moiety X)) motif 17; Nucleoside diphosphate-linked moiety X)) motif 17 (EC 3.6.1.-) encoded by the NUDT17 gene on chromosome 1q21.1 and encodes an enzyme thought to hydrolyse some nucleoside diphosphate derivatives. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  78 VDLGVAVILQSSDQTVLLTRRTCTLRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQfSCVLLGLWESAYPP 157
Cdd:cd04694    1 VDVGVVVLIEDSDDRVLLTRRAKHMRTFPGVWVPPGGHVELGESLLEAGLRELQEETGLEVSDIQ-SLSLLGLWESVYPT 79

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 568924547 158 RLSWGFPKYHHLILYVLVISQESQeQLQARIQVNPNEVNAFMWLGPDVAAAVVATED 214
Cdd:cd04694   80 LLSIGLPKRHHIVVYYLVKLSESH-ENQEQLKLQEDEVDAAVWLPKSLLAKLLEAED 135

nucleoside diphosphate-linked moiety X)) motif 17; Nucleoside diphosphate-linked moiety X)) motif 17 (EC 3.6.1.-) encoded by the NUDT17 gene on chromosome 1q21.1 and encodes an enzyme thought to hydrolyse some nucleoside diphosphate derivatives. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  78 VDLGVAVILQSSDQTVLLTRRTCTLRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQfSCVLLGLWESAYPP 157
Cdd:cd04694    1 VDVGVVVLIEDSDDRVLLTRRAKHMRTFPGVWVPPGGHVELGESLLEAGLRELQEETGLEVSDIQ-SLSLLGLWESVYPT 79

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 568924547 158 RLSWGFPKYHHLILYVLVISQESQeQLQARIQVNPNEVNAFMWLGPDVAAAVVATED 214
Cdd:cd04694   80 LLSIGLPKRHHIVVYYLVKLSESH-ENQEQLKLQEDEVDAAVWLPKSLLAKLLEAED 135

8-oxo-dGTP pyrophosphatase MutT and related house-cleaning NTP pyrophosphohydrolases, NUDIX family [Defense mechanisms];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  81 GVAVILQSSDQTVLLTRRTcTLRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQfscvLLGLWESaypprls 160
Cdd:COG0494   15 AVVVVLLDDDGRVLLVRRY-RYGVGPGLWEFPGGKIEPGESPEEAALRELREETGLTAEDLE----LLGELPS------- 82

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568924547 161 wgfPKYHHLILYV---LVISQESQEQLQAriqvnPNEVNAFMWLGPDVAAAVVATEDGTRT 218
Cdd:COG0494   83 ---PGYTDEKVHVflaRGLGPGEEVGLDD-----EDEFIEVRWVPLDEALALVTAGEIAKT 135

mutator mutT protein; All proteins in this family for which functions are known are involved in repairing oxidative damage to dGTP (they are 8-oxo-dGTPases). This family is based on the phylogenomic analysis of JA Eisen (1999, Ph.D. Thesis, Stanford University). Lowering the threshold picks up members of MutT superfamily well. [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547   82 VAVILQSSDQTVLLTRRTCTLRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQlpknqfscVLLGLWEsayppRLSW 161
Cdd:TIGR00586   6 IAVGIIRNENGEIIITRRADGHMFAKLLEFPGGKEEGGETPEQAVVRELEEEIGIP--------QHFSEFE-----KLEY 72

                          90       100
                  ....*....|....*....|.
gi 568924547  162 GFPKYHHLILYVLVISQESQE 182
Cdd:TIGR00586  73 EFYPRHITLWFWLLERWEGGP 93

nucleoside diphosphate-linked moiety X)) motif 17; Nucleoside diphosphate-linked moiety X)) motif 17 (EC 3.6.1.-) encoded by the NUDT17 gene on chromosome 1q21.1 and encodes an enzyme thought to hydrolyse some nucleoside diphosphate derivatives. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  78 VDLGVAVILQSSDQTVLLTRRTCTLRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQfSCVLLGLWESAYPP 157
Cdd:cd04694    1 VDVGVVVLIEDSDDRVLLTRRAKHMRTFPGVWVPPGGHVELGESLLEAGLRELQEETGLEVSDIQ-SLSLLGLWESVYPT 79

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 568924547 158 RLSWGFPKYHHLILYVLVISQESQeQLQARIQVNPNEVNAFMWLGPDVAAAVVATED 214
Cdd:cd04694   80 LLSIGLPKRHHIVVYYLVKLSESH-ENQEQLKLQEDEVDAAVWLPKSLLAKLLEAED 135

NUDIX domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547   80 LGVAVILQSSDQTVLLTRRTCtlRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFscvlLGLWESAYPPRL 159
Cdd:pfam00293   4 VAVGVVLLNEKGRVLLVRRSK--KPFPGWWSLPGGKVEPGETPEEAARRELEEETGLEPELLEL----LGSLHYLAPFDG 77

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*....
gi 568924547  160 SWGFPkyhHLILYVLVISQESQEQLQAriqvnPNEVNAFMWLGPDVAAA 208
Cdd:pfam00293  78 RFPDE---HEILYVFLAEVEGELEPDP-----DGEVEEVRWVPLEELLL 118

MutT homolog 2; MutT Homolog 2 (MTH2; EC 3.6.1.9), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 15/Nudt15, may catalyze the hydrolysis of nucleoside diphosphates, triphosphates including dGTP, dTTP, dCTP, their oxidized forms like 8-oxo-dGTP, and prodrug thiopurine derivatives 6-thio-dGTP and 6-thio-GTP. MTH2 may also play a role in DNA synthesis and cell cycle progression by stabilizing PCNA. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 568924547  81 GVAVILQSSDQTVLLTRRTCTLRisPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFSCVL 147
Cdd:cd04678    4 GVGVIVLNDDGKVLLGRRKGSHG--AGTWALPGGHLEFGESFEECAAREVLEETGLEIRNVRFLTVT 68

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 568924547  81 GVAVILQSSDQTVLLTRRTCTLRI-SPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFSCV 146
Cdd:cd18882    3 VAIAILYDDRGKVLLQLRDDKPGIpYPGYWGLFGGHLEPGETPEEAIRRELEEEIGYEPGEFRFFLL 69

MutT homolog-1 and similar proteins; MutT homolog-1 (MTH1), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 1/Nudt1, is a member of the NUDIX hydrolase superfamily. MTH1, the mammalian counterpart of MutT, hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP and 2-hydroxy-ATP, to monophosphates, thereby preventing the incorporation of such oxygen radicals during replication. This is an important step in the repair mechanism in genomic and mitochondrial DNA. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity, and contain the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. MTH1 is predominantly localized in the cytoplasm and mitochondria. Structurally, this enzyme adopts a similar fold to MutT despite low sequence similarity outside the conserved NUDIX motif. The most distinctive structural difference between MutT and MTH1 is the presence of a beta-hairpin, which is absent in MutT. This results in a much deeper and narrower substrate binding pocket. Mechanistically, MTH1 contains dual specificity for nucleotides that contain 2-OH-adenine bases and those that contain 8-oxo-guanine bases.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 568924547  85 ILQSSDQTVLLTRRTctlRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFSCVL 147
Cdd:cd18886    6 FIIRDDEVLLLNRNK---KPNMGKWNGVGGKLEPGESPEECAIREVFEETGLELEDLQLRGIV 65

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 568924547  83 AVILQSSDQTVLLTRRtctlRISpNLWVPPGGHMEPDEEILECGFRELWEECGLQL 138
Cdd:cd03674    6 AFVVNPDRGKVLLVHH----RKL-GRWLQPGGHVEPDEDPLEAALREAREETGLDV 56

MutT homolog-1 (MTH1); MutT homolog-1 (MTH1; EC 3.6.1.- ), also called nucleoside diphosphate-linked moiety X)) motif 1 (Nudt1), is a member of the NUDIX hydrolase superfamily. MTH1, the mammalian counterpart of MutT, hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP and 2-hydroxy-ATP, to monophosphates, thereby preventing the incorporation of such oxygen radicals during replication. This is an important step in the repair mechanism in genomic and mitochondrial DNA. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity, and contain the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. MTH1 is predominantly localized in the cytoplasm and mitochondria. Structurally, this enzyme adopts a similar fold to MutT despite low sequence similarity outside the conserved NUDIX motif. The most distinctive structural difference between MutT and MTH1 is the presence of a beta-hairpin, which is absent in MutT. This results in a much deeper and narrower substrate binding pocket. Mechanistically, MTH1 contains dual specificity for nucleotides that contain 2-OH-adenine bases and those that contain 8-oxo-guanine bases.

                         10        20        30
                 ....*....|....*....|....*....|...
gi 568924547 107 NLWVPPGGHMEPDEEILECGFRELWEECGLQLP 139
Cdd:cd03427   27 GKWNGFGGKVEPGETIEEAAVRELEEEAGLTAT 59

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 568924547  81 GVAVILQSSDQTVLLTRRTctlriSPNLWVPPGGHMEPDEEILECGFRELWEECGLQL 138
Cdd:cd04677   14 GAAVIILNEQGRILLQKRT-----DTGDWGLPGGAMELGESLEETARREVFEETGLTV 66

diadenosine tetraphosphate; Diadenosine tetraphosphate (Ap4A; EC 3.6.1.17), also called NUDIX (nucleoside diphosphate-linked moiety X)) motif 2/Nudt2, is a member of the NUDIX hydrolase superfamily. Ap4A hydrolases are well represented in a variety of prokaryotic and eukaryotic organisms. Phylogenetic analysis reveals two distinct subgroups where plant enzymes fall into one subfamily and fungi/animals/archaea enzymes, represented by this subfamily, fall into another. Bacterial enzymes are found in both subfamilies. Ap4A is a potential by-product of aminoacyl tRNA synthesis, and accumulation of Ap4A has been implicated in a range of biological events, such as DNA replication, cellular differentiation, heat shock, metabolic stress, and apoptosis. Ap4A hydrolase cleaves Ap4A asymmetrically into ATP and AMP. It is important in the invasive properties of bacteria and thus presents a potential target for inhibition of such invasive bacteria. Besides the signature NUDIX motif (G[X5]E[X7]REUXEEXGU, where U is Ile, Leu, or Val) that functions as a metal binding and catalytic site, and a required divalent cation, Ap4A hydrolase is structurally similar to the other members of the NUDIX hydrolase superfamily with some degree of variation. Several regions in the sequences are poorly defined and substrate and metal binding sites are only predicted based on kinetic studies.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547 109 WVPPGGHMEPDEEILECGFRELWEECGL---QLPKNqFSCVLlglwesAYPPRlsWGFPKyhHLILYVLVISQESQEQLQ 185
Cdd:cd03428   30 WDFPKGHVEPGESELETALRETKEETGLtvdDLPPG-FRETL------TYSFK--EGVEK--TVVYFLAELTPDVEVKLS 98

                         90
                 ....*....|....*.
gi 568924547 186 AriqvnpnEVNAFMWL 201
Cdd:cd03428   99 E-------EHQDYKWL 107

dihydroneopterin hydrolase; DHNTP pyrophosphatase (DHNTPase) catalyzes the hydrolysis of dihydroneopterin triphosphate (DHNTP) to dihydroneopterin monophosphate (DHNMP) and pyrophosphate,the second step in the pterin branch of the folate synthesis pathway in bacteria. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  80 LGVAVILQSSDQtVLLTRRTCTlrisPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFSCVLLglwESAYPPRL 159
Cdd:cd04664    4 LVVIYRKDEEGE-VLLLKRTDD----GGFWQSVTGGIEDGETPWQAALRELKEETGLDPLELQLIDLNV---SNFYEIFD 75

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|.
gi 568924547 160 SWgFPKYHHLILYVLVISQESQEQlqarIQVNPnEVNAFMWLGPDVAAAVV 210
Cdd:cd04664   76 DW-RPGVTVNTEHVFAVEVPEEQP----IRLSP-EHTDYRWLPYEEAAELL 120

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  80 LGVAVILQSSDQTVLLTRRTctlriSPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFSCVllgLWESAYPPRl 159
Cdd:cd18876    1 AAAGALFTDAAGRVLLVKPT-----YKDGWELPGGVVEAGESPLQAARREVREELGLDVPVGRLLAV---DWVPPAGGG- 71

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|.
gi 568924547 160 swgfPKYHHLILYVLVISqesqEQLQARIQVNPNEVNAFMWLGPDVAAAVV 210
Cdd:cd18876   72 ----DDAVLFVFDGGVLT----PEQAAAIRLQDEELSAYRFVTPEEAAELL 114

RNA pyrophosphohydrolase; The initiation of mRNA degradation often requires deprotection of its 5' end. In eukaryotes, the 5'-methylguanosine (cap) structure is principally removed by the NUDIX family decapping enzyme Dcp2, yielding a 5'-monophosphorylated RNA that is a substrate for 5' exoribonucleases. In bacteria, the 5'-triphosphate group of primary transcripts is also converted to a 5' monophosphate by a NUDIX protein called RNA pyrophosphohydrolase (RppH), allowing access to both endo- and 5' exoribonucleases. NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 568924547  82 VAVILQSSDQtVLLT----RRTctlrispnlWVPPGGHMEPDEEILECGFRELWEECG 135
Cdd:cd04665    3 VVVIARYKGK-WLFTrhkeRRG---------WEFPGGKREPGETIEEAARRELYEETG 50

Nudix family hydrolase;

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  78 VDLGVAVILQSSDQtVLLTRRTCTlRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQ 137
Cdd:PRK08999   5 IHVAAGVIRDADGR-ILLARRPEG-KHQGGLWEFPGGKVEPGETVEQALARELQEELGIE 62

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 568924547  82 VAVILQSSDQtVLLTRRtctlRISP--NLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFSC 145
Cdd:cd04681    9 VGVIIRNEGE-ILFVRR----AKEPgkGKLDLPGGFVDPGESAEEALRRELREELGLKIPKLRYLC 69

diadenosine hexaphosphate (Ap6A) hydrolase; Diadenosine hexaphosphate (Ap6A) hydrolase is a member of the NUDIX hydrolase superfamily. Ap6A hydrolase specifically hydrolyzes diadenosine polyphosphates, but not ATP or diadenosine triphosphate, and it generates ATP as the product. Ap6A, the most preferred substrate, hydrolyzes to produce two ATP molecules, which is a novel hydrolysis mode for Ap6A. These results indicate that Ap6A hydrolase is a diadenosine polyphosphate hydrolase. It requires the presence of a divalent cation, such as Mn2+, Mg2+, Zn2+, and Co2+, for activity. Members of the NUDIX hydrolase superfamily are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site.

                         10        20
                 ....*....|....*....|....*....
gi 568924547 109 WVPPGGHMEPDEEILECGFRELWEECGLQ 137
Cdd:cd03673   29 WSLPKGKLEPGETPEEAAVREVEEETGLR 57

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 568924547  83 AVILQSSDQTVLLTRRTctlRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPKNQFSCVLL 148
Cdd:cd04669    3 AVLVIYDDDKLLLIRRT---KPGEEYYVFPGGGIEPGETPEEAALREAVEELGLDVAVTLITLILR 65

coenzyme A pyrophosphatase and similar proteins; Coenzyme A pyrophosphatase (CoAse; EC 3.6.1.1), also called nucleoside diphosphate-linked moiety X)) motif 7, is a member of the NUDIX hydrolase superfamily, functions to catalyze the elimination of oxidized inactive CoA, which can inhibit CoA-utilizing enzymes. The need of CoAses mainly arises under conditions of oxidative stress. CoAse has a conserved NUDIX fold and requires a single divalent cation for catalysis. In addition to a signature NUDIX motif G[X5]E[X7]REUXEEXGU, where U is Ile, Leu, or Val, CoAse contains an additional motif upstream called the NuCoA motif (LLTXT(SA)X3RX3GX3FPGG) which is postulated to be involved in CoA recognition. CoA plays a central role in lipid metabolism. It is involved in the initial steps of fatty acid sythesis in the cytosol, in the oxidation of fatty acids and the citric acid cycle in the mitochondria, and in the oxidation of long-chain fatty acids in peroxisomes. CoA has the important role of activating fatty acids for further modification into key biological signalling molecules.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 568924547  82 VAVILQSSDQ--TVLLTRRTCTLR-----ISpnLwvpPGGHMEP-DEEILECGFRELWEECGLQL 138
Cdd:cd03426    5 VLIPLVEGDGelHVLLTKRASHLRshpgqIA--F---PGGKREPgDESPVETALRETEEEIGLPP 64

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 568924547  81 GV-AVILQSSDQtVLLTRRTCTLRispnlWVPPGGHMEPDEEILECGFRELWEECGLQ 137
Cdd:cd18879   20 GVtAVVLRDAGR-VLLVRRADNGR-----WTPVTGIVEPGEQPADAAVREVLEETGVD 71

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 568924547  84 VILQSSDQTVLLTRRTCTLRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQLP 139
Cdd:cd04685    5 VLLLDPDGRVLLFRFHDPDDPGRSWWFTPGGGVEPGESPEQAAVRELREETGLRLE 60

plant diadenosine tetraphosphate (Ap4A) hydrolase and similar proteins; Diadenosine tetraphosphate (Ap4A) hydrolase is a member of the NUDIX hydrolase superfamily. Members of this family are well represented in a variety of prokaryotic and eukaryotic organisms. Phylogenetic analysis reveals two distinct subgroups where plant enzymes fall into one group (represented by this subfamily) and fungi/animals/archaea enzymes fall into another. Bacterial enzymes are found in both subfamilies. Ap4A is a potential by-product of aminoacyl tRNA synthesis, and accumulation of Ap4A has been implicated in a range of biological events, such as DNA replication, cellular differentiation, heat shock, metabolic stress, and apoptosis. Ap4A hydrolase cleaves Ap4A asymmetrically into ATP and AMP. It is important in the invasive properties of bacteria and thus presents a potential target for the inhibition of such invasive bacteria. Besides the signature NUDIX motif (G[X5]E[X7]REUXEEXGU where U is Ile, Leu, or Val), Ap4A hydrolase is structurally similar to the other members of the NUDIX hydrolase superfamily with some degree of variations. Several regions in the sequences are poorly defined and substrate and metal binding sites are only predicted based on kinetic studies.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  81 GVAVILQSSDQTVLLTRRTCTlrisPNLWVPPGGHMEPDEEILECGFRELWEECGLQLPK 140
Cdd:cd03671    5 NVGIVLFNRDGQVLVGRRIDV----PGAWQFPQGGIDEGEDPEEAALRELYEETGLSPED 60

bifunctional NMN adenylyltransferase/ADP-ribose pyrophosphatase and similar proteins; Bacterial NadM-Nudix is a bifunctional enzyme containing a nicotinamide mononucleotide (NMN) adenylyltransferase (NMNAT) and an ADP-ribose pyrophosphatase (ADPRase) domain. NMNAT was initially identified as an NAD+ synthase that catalyzes the reversible conversion of NMN to NAD+ in the final step of both the de novo biosynthesis and salvage pathways in most organisms across all three kingdoms of life ADPRase is a member of the NUDIX family proteins, catalyzes the metal-induced and concerted general acid-base hydrolysis of ADP ribose (ADPR) into AMP and ribose-5'-phosphate (R5P). Additional members in this cd include bacterial transcriptional regulator, NrtR, which represses the transcription of NAD biosynthetic genes in vitro and adenosine diphosphate ribose (ADPR), as well as NadQ, a NUDIX-like ATP-responsive regulator of NAD biosynthesis. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belong to this superfamily requires a divalent cation, such as Mg2+ or Mn2+ for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, U=I, L or V) which functions as metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 568924547  78 VDlgvAVILQSSDQT--VLLTRRtctlRISP--NLWVPPGGHMEPDEEILECGFRELWEECGLQLP 139
Cdd:cd18873    5 VD---CVIFGFDDGElkVLLIKR----KNEPfkGGWALPGGFVREDETLEDAARRELREETGLKDI 63

RNA pyrophosphohydrolase; Reviewed

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 568924547  82 VAVILQSSDQTVLLTRRTctlrISPNLWVPPGGHMEPDEEILECGFRELWEECGLQ 137
Cdd:PRK00714  11 VGIILLNRQGQVFWGRRI----GQGHSWQFPQGGIDPGETPEQAMYRELYEEVGLR 62

diadenosine 5',5'''-P1,P6-hexaphosphate hydrolase type 2 and similar proteins; Diadenosine 5',5'''-P1,P6-hexaphosphate hydrolase type 2 (DIPP2), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 4; Nudt4, and other proteins including DIPP1/Nudt3, DIPP3a;APS2/Nudt10 and DIPP3beta;APS1/Nudt11. DIPP regulates the turnover of diphosphoinositol polyphosphates. The turnover of these high-energy diphosphoinositol polyphosphates represents a molecular switching activity with important regulatory consequences. Molecular switching by diphosphoinositol polyphosphates may contribute to regulating intracellular trafficking. Several alternatively spliced transcript variants have been described, but the full-length nature of some variants has not been determined. Isoforms DIPP2alpha and DIPP2beta are distinguishable from each other solely by DIPP2beta possessing one additional amino acid due to intron boundary skidding in alternate splicing. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  93 VLL--TRRTctlrispNLWVPPGGHMEPDEEILECGFRELWEECGL---QLPKnqfscvLLGLWEsaYPPRLSWGFPKYH 167
Cdd:cd04666   17 VLLitSRKT-------GRWILPKGGPEKGETPAEAAAREAWEEAGVrgkVLKR------PLGVYR--YRKRLKGRGLPCR 81

                         90
                 ....*....|....*
gi 568924547 168 HLIlYVLVISQESQE 182
Cdd:cd04666   82 VHV-FPLEVTEELDD 95

uncharacterized NUDIX hydrolase subfamily; Contains a crystal structure of the NUDIX hydrolase from Nitrosomonas europaea, which has an unknown function. NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20
                 ....*....|....*....|....*..
gi 568924547 112 PGGHMEPDEEILECGFRELWEECGLQL 138
Cdd:cd03675   29 PAGHLEPGESLLEAAIRETLEETGWEV 55

mutator mutT protein; All proteins in this family for which functions are known are involved in repairing oxidative damage to dGTP (they are 8-oxo-dGTPases). This family is based on the phylogenomic analysis of JA Eisen (1999, Ph.D. Thesis, Stanford University). Lowering the threshold picks up members of MutT superfamily well. [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547   82 VAVILQSSDQTVLLTRRTCTLRISPNLWVPPGGHMEPDEEILECGFRELWEECGLQlpknqfscVLLGLWEsayppRLSW 161
Cdd:TIGR00586   6 IAVGIIRNENGEIIITRRADGHMFAKLLEFPGGKEEGGETPEQAVVRELEEEIGIP--------QHFSEFE-----KLEY 72

                          90       100
                  ....*....|....*....|.
gi 568924547  162 GFPKYHHLILYVLVISQESQE 182
Cdd:TIGR00586  73 EFYPRHITLWFWLLERWEGGP 93

Bdellovibrio Bacteriovorus nucleoside diphosphate sugar hydrolase, and similar proteins; Bdellovibrio bacteriovorus nucleoside diphosphate sugar (NDPS) hydrolase Bd3179 has been shown to similarities to the Escherichia coli adenosine diphosphate ribose (ADPR) hydrolase and the guanosine diphosphate mannose (GDPM) hydrolase. It may have a role when Bdellovibrio degrades and metabolizes host cell. ADP-ribose pyrophosphatase (ADPRase) catalyzes the hydrolysis of ADP-ribose and a variety of additional ADP-sugar conjugates to AMP and ribose-5-phosphate. In humans, there are four distinct ADPRase activities, three putative cytosolic enzymes (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). Human ADPRase-II is also referred to as NUDT5. It lacks the N-terminal target sequence unique to mitochondrial ADPRase. The different cytosolic types are distinguished by their specificities for substrate and specific requirement for metal ions. NUDT5 forms a homodimer. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity. UDP-glucose pyrophosphatase (UGPPase) (EC 3.6.1.45; also known as nucleoside diphosphate-linked moiety X)) motif 14; Nudt14) hydrolyzes the pyrophosphate of the nucleoside diphosphate sugar to generate glucose-1-P and UMP. In mammals, UDP-glucose is the glucosyl donor for the synthesis of the storage polysaccharide glycogen. UGPPase, as a regulator of UDP-glucose, could play a regulatory role, but it has been shown to prefer ADP-ribose over UDP-glucose. Like other members of the NUDIX hydrolase superfamily, it requires a divalent cation, such as Mg2+, for its activity. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 568924547  66 EVSKTEPLTNRGvdlGVAVILQSSDQTVLLTRRtctLR--ISPNLWVPPGGHMEPDEEILECGFRELWEECG 135
Cdd:cd24159   31 STSTREYITHPG---AVAVVPLLDDGRVVMERQ---YRypLKRVFLEFPAGKIDPGEDTLETAKRELLEETG 96

isopentenyl-diphosphate delta-isomerase

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568924547  84 VILQSSDQTVLLTRRTCTLRISPNLWVP-----PGGHMEPDEEILECGF-------------RELWEECGL---QLPKNQ 142
Cdd:PLN02552  61 VFLFNSKYELLLQQRAATKVTFPLVWTNtccshPLYGQDPNEVDRESELidgnvlgvknaaqRKLLHELGIpaeDVPVDQ 140

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568924547 143 FSCVLLGLW----ESAYPPRLSWGfpkyHHLILYVLVISQESQeqlqARIQVNPNEVNAFMWLGPDVAAAVVATEDGTR 217
Cdd:PLN02552 141 FTFLTRLHYkaadDVTHGPDGKWG----EHELDYLLFIRPVRD----VKVNPNPDEVADVKYVNREELKEMMRKESGLK 211

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 568924547  81 GVAVILQSSDQTVLLTRRTCTlrispNLWVPPGGHMEPDEEILECGFRELWEECGLQL 138
Cdd:cd04676   19 SVAAVILNEDGRILLQRKGGL-----GLWSLPAGAIEPGEHPAEAVIREVREETGLLV 71