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Conserved domains on  [gi|21732393|emb|CAD38567|]
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hypothetical protein, partial [Homo sapiens]

Protein Classification

acyl-CoA desaturase( domain architecture ID 10131286)

acyl-CoA desaturase removes two hydrogen atoms from a fatty acid, creating a carbon/carbon double bond; similar to acyl-CoA delta(9) desaturase and acyl-CoA delta(11) desaturase

EC:  1.14.19.-
Gene Ontology:  GO:0046872|GO:0016020|GO:0006633|GO:0016717
PubMed:  9767077

Graphical summary

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List of domain hits

 Name Accession Description Interval E-value
Delta9-FADS-like cd03505
The Delta9 Fatty Acid Desaturase (Delta9-FADS)-like CD includes the delta-9 and delta-11 acyl ...
 45-141 7.96e-37

The Delta9 Fatty Acid Desaturase (Delta9-FADS)-like CD includes the delta-9 and delta-11 acyl CoA desaturases found in various eukaryotes including vertebrates, insects, higher plants, and fungi. The delta-9 acyl-lipid desaturases are found in a wide range of bacteria. These enzymes play essential roles in fatty acid metabolism and the regulation of cell membrane fluidity. Acyl-CoA desaturases are the enzymes involved in the CoA-bound desaturation of fatty acids. Mammalian stearoyl-CoA delta-9 desaturase is a key enzyme in the biosynthesis of monounsaturated fatty acids, and in yeast, the delta-9 acyl-CoA desaturase (OLE1) reaction accounts for all de nova unsaturated fatty acid production in Saccharomyces cerevisiae. These non-heme, iron-containing, ER membrane-bound enzymes are part of a three-component enzyme system involving cytochrome b5, cytochrome b5 reductase, and the delta-9 fatty acid desaturase. This complex catalyzes the NADH- and oxygen-dependent insertion of a cis double bond between carbons 9 and 10 of the saturated fatty acyl substrates, palmitoyl (16:0)-CoA or stearoyl (18:0)-CoA, yielding the monoenoic products palmitoleic (16:l) or oleic (18:l) acids, respectively. In cyanobacteria, the biosynthesis of unsaturated fatty acids is initiated by delta 9 acyl-lipid desaturase (DesC) which introduces the first double bond at the delta-9 position of a saturated fatty acid that has been esterified to a glycerolipid. This domain family has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of sequences also reveals the existence of three regions of conserved histidine cluster motifs that contain the residues: HXXXXH, HXXHH, and H/QXXHH. These histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the rat stearoyl CoA delta-9 desaturase. Some eukaryotic (Fungi, Euglenozoa, Mycetozoa, Rhodophyta) desaturase domains have an adjacent C-terminal cytochrome b5-like domain.


:

Pssm-ID: 239582  Cd Length: 178  Bit Score: 124.59  E-value: 7.96e-37
                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393  45 SLWNSYF--LASILRYTISLNISWLVNSAAHMYGNRPYDKHISPRQNPLVALGAIGEGFHNYHHTFPFDYSASEFGLNFN 122
Cdd:cd03505  80 GFWFSHVgwLGGLLRIVLVLHATWLVNSLAHMWGYRPYDTRDTSRNNWWVALLTFGEGWHNNHHAFPGDARNGLKWYQID 159

                        90
                ....*....|....*....
gi 21732393 123 PTTWFIDFMCWLGLATDRK 141
Cdd:cd03505 160 PTKWVIRLLEKLGLAWDLK 178
 
Name Accession Description Interval E-value
Delta9-FADS-like cd03505
The Delta9 Fatty Acid Desaturase (Delta9-FADS)-like CD includes the delta-9 and delta-11 acyl ...
 45-141 7.96e-37

The Delta9 Fatty Acid Desaturase (Delta9-FADS)-like CD includes the delta-9 and delta-11 acyl CoA desaturases found in various eukaryotes including vertebrates, insects, higher plants, and fungi. The delta-9 acyl-lipid desaturases are found in a wide range of bacteria. These enzymes play essential roles in fatty acid metabolism and the regulation of cell membrane fluidity. Acyl-CoA desaturases are the enzymes involved in the CoA-bound desaturation of fatty acids. Mammalian stearoyl-CoA delta-9 desaturase is a key enzyme in the biosynthesis of monounsaturated fatty acids, and in yeast, the delta-9 acyl-CoA desaturase (OLE1) reaction accounts for all de nova unsaturated fatty acid production in Saccharomyces cerevisiae. These non-heme, iron-containing, ER membrane-bound enzymes are part of a three-component enzyme system involving cytochrome b5, cytochrome b5 reductase, and the delta-9 fatty acid desaturase. This complex catalyzes the NADH- and oxygen-dependent insertion of a cis double bond between carbons 9 and 10 of the saturated fatty acyl substrates, palmitoyl (16:0)-CoA or stearoyl (18:0)-CoA, yielding the monoenoic products palmitoleic (16:l) or oleic (18:l) acids, respectively. In cyanobacteria, the biosynthesis of unsaturated fatty acids is initiated by delta 9 acyl-lipid desaturase (DesC) which introduces the first double bond at the delta-9 position of a saturated fatty acid that has been esterified to a glycerolipid. This domain family has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of sequences also reveals the existence of three regions of conserved histidine cluster motifs that contain the residues: HXXXXH, HXXHH, and H/QXXHH. These histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the rat stearoyl CoA delta-9 desaturase. Some eukaryotic (Fungi, Euglenozoa, Mycetozoa, Rhodophyta) desaturase domains have an adjacent C-terminal cytochrome b5-like domain.


Pssm-ID: 239582  Cd Length: 178  Bit Score: 124.59  E-value: 7.96e-37
                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393  45 SLWNSYF--LASILRYTISLNISWLVNSAAHMYGNRPYDKHISPRQNPLVALGAIGEGFHNYHHTFPFDYSASEFGLNFN 122
Cdd:cd03505  80 GFWFSHVgwLGGLLRIVLVLHATWLVNSLAHMWGYRPYDTRDTSRNNWWVALLTFGEGWHNNHHAFPGDARNGLKWYQID 159

                        90
                ....*....|....*....
gi 21732393 123 PTTWFIDFMCWLGLATDRK 141
Cdd:cd03505 160 PTKWVIRLLEKLGLAWDLK 178
OLE1 COG1398
Fatty-acid desaturase [Lipid transport and metabolism];
6-150 5.12e-30

Fatty-acid desaturase [Lipid transport and metabolism];


Pssm-ID: 441008  Cd Length: 286  Bit Score: 110.30  E-value: 5.12e-30
                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393   6 VTDLLADPVVRIQRKYYKISVVLMCFVVPTLVPWyiWGESLWNSYFLASILRYTISLNISWLVNSAAHMYGNRPYDKHIS 85
Cdd:COG1398 144 APDLAKDPELRWLDRYYLLLQLALGLLLPALLGG--LLGGGWSGLLWGGFVRTVLLHHGTWFINSLAHVWGYRPFETRDT 221

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 21732393  86 PRQNPLVALGAIGEGFHNYHHTFPFDYSaseFGL---NFNPTTWFIDFMCWLGLATDRKRATKPMIEA 150
Cdd:COG1398 222 SRNNWWLALLTFGEGWHNNHHAFPTSAR---HGLrwwEIDPTWWLIRLLEKLGLAWDVRRPPAERIAA 286
PLN02220 PLN02220
delta-9 acyl-lipid desaturase
 59-144 2.45e-07

delta-9 acyl-lipid desaturase


Pssm-ID: 177866 [Multi-domain]  Cd Length: 299  Bit Score: 48.65  E-value: 2.45e-07
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393   59 TISLNISWLVNSAAHMYGNRPYDKHISPRQNPLVALGAIGEGFHNYHHTFPfdySASEFGLNFNPT--TWF-IDFMCWLG 135
Cdd:PLN02220 203 AIGYHVTWLINSACHIWGSRTWKTKDTSRNVWWLSLFTMGESWHNNHHAFE---SSARQGLEWWQIdiTWYlIRFFEVLG 279


                 ....*....
gi 21732393  136 LATDRKRAT 144
Cdd:PLN02220 280 LATDVKLPT 288
FA_desaturase pfam00487
Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a ...
 9-109 3.29e-03

Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a double bond at the delta position of fatty acids. There seem to be two distinct families of fatty acid desaturases which do not seem to be evolutionary related: Family 1 composed of Stearoyl-CoA desaturases (SCD) and Family 2 composed of Bacterial fatty acid desaturases, Plant stearoyl-acyl-carrier-protein desaturase and Cyanobacterial DesA. Members of this entry are ER integral membrane proteins that share the same mushroom-shaped fold consisting of four transmembrane helices (TM1-TM4) which anchor them to the membrane, capped by a cytosolic domain containing a unique 9-10 histidine- coordinating di metal (di-iron) catalytic centre. The structure of mouse stearoyl-CoA desaturase (SDC) revealed that TM2 and TM4 are longer than TM1 and TM3 and protrude into the cytosolic domain, providing three of the nine histidine residues that coordinate the two metal ions, while the other histidine residues are provided by the soluble domain in this enzyme.


Pssm-ID: 425713 [Multi-domain]  Cd Length: 252  Bit Score: 36.56  E-value: 3.29e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393     9 LLADPVVRIQRKYYKISVVLMCFVVPTLVPWYIWGESLWNSYFLASIlryTISLNISWLVNSAAHmYGNRPYDKHISPR- 87
Cdd:pfam00487 122 RKRPIKSRRRRWRLIAWLLLLAAWLGLWLGFLGLGGLLLLLWLLPLL---VFGFLLALIFNYLEH-YGGDWGERPVETTr 197

                          90       100
                  ....*....|....*....|....*.
gi 21732393    88 ----QNPLVALGAIGEGFHNYHHTFP 109
Cdd:pfam00487 198 sirsPNWWLNLLTGNLNYHIEHHLFP 223
 
Name Accession Description Interval E-value
Delta9-FADS-like cd03505
The Delta9 Fatty Acid Desaturase (Delta9-FADS)-like CD includes the delta-9 and delta-11 acyl ...
 45-141 7.96e-37

The Delta9 Fatty Acid Desaturase (Delta9-FADS)-like CD includes the delta-9 and delta-11 acyl CoA desaturases found in various eukaryotes including vertebrates, insects, higher plants, and fungi. The delta-9 acyl-lipid desaturases are found in a wide range of bacteria. These enzymes play essential roles in fatty acid metabolism and the regulation of cell membrane fluidity. Acyl-CoA desaturases are the enzymes involved in the CoA-bound desaturation of fatty acids. Mammalian stearoyl-CoA delta-9 desaturase is a key enzyme in the biosynthesis of monounsaturated fatty acids, and in yeast, the delta-9 acyl-CoA desaturase (OLE1) reaction accounts for all de nova unsaturated fatty acid production in Saccharomyces cerevisiae. These non-heme, iron-containing, ER membrane-bound enzymes are part of a three-component enzyme system involving cytochrome b5, cytochrome b5 reductase, and the delta-9 fatty acid desaturase. This complex catalyzes the NADH- and oxygen-dependent insertion of a cis double bond between carbons 9 and 10 of the saturated fatty acyl substrates, palmitoyl (16:0)-CoA or stearoyl (18:0)-CoA, yielding the monoenoic products palmitoleic (16:l) or oleic (18:l) acids, respectively. In cyanobacteria, the biosynthesis of unsaturated fatty acids is initiated by delta 9 acyl-lipid desaturase (DesC) which introduces the first double bond at the delta-9 position of a saturated fatty acid that has been esterified to a glycerolipid. This domain family has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of sequences also reveals the existence of three regions of conserved histidine cluster motifs that contain the residues: HXXXXH, HXXHH, and H/QXXHH. These histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the rat stearoyl CoA delta-9 desaturase. Some eukaryotic (Fungi, Euglenozoa, Mycetozoa, Rhodophyta) desaturase domains have an adjacent C-terminal cytochrome b5-like domain.


Pssm-ID: 239582  Cd Length: 178  Bit Score: 124.59  E-value: 7.96e-37
                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393  45 SLWNSYF--LASILRYTISLNISWLVNSAAHMYGNRPYDKHISPRQNPLVALGAIGEGFHNYHHTFPFDYSASEFGLNFN 122
Cdd:cd03505  80 GFWFSHVgwLGGLLRIVLVLHATWLVNSLAHMWGYRPYDTRDTSRNNWWVALLTFGEGWHNNHHAFPGDARNGLKWYQID 159

                        90
                ....*....|....*....
gi 21732393 123 PTTWFIDFMCWLGLATDRK 141
Cdd:cd03505 160 PTKWVIRLLEKLGLAWDLK 178
OLE1 COG1398
Fatty-acid desaturase [Lipid transport and metabolism];
6-150 5.12e-30

Fatty-acid desaturase [Lipid transport and metabolism];


Pssm-ID: 441008  Cd Length: 286  Bit Score: 110.30  E-value: 5.12e-30
                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393   6 VTDLLADPVVRIQRKYYKISVVLMCFVVPTLVPWyiWGESLWNSYFLASILRYTISLNISWLVNSAAHMYGNRPYDKHIS 85
Cdd:COG1398 144 APDLAKDPELRWLDRYYLLLQLALGLLLPALLGG--LLGGGWSGLLWGGFVRTVLLHHGTWFINSLAHVWGYRPFETRDT 221

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 21732393  86 PRQNPLVALGAIGEGFHNYHHTFPFDYSaseFGL---NFNPTTWFIDFMCWLGLATDRKRATKPMIEA 150
Cdd:COG1398 222 SRNNWWLALLTFGEGWHNNHHAFPTSAR---HGLrwwEIDPTWWLIRLLEKLGLAWDVRRPPAERIAA 286
PLN02220 PLN02220
delta-9 acyl-lipid desaturase
 59-144 2.45e-07

delta-9 acyl-lipid desaturase


Pssm-ID: 177866 [Multi-domain]  Cd Length: 299  Bit Score: 48.65  E-value: 2.45e-07
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393   59 TISLNISWLVNSAAHMYGNRPYDKHISPRQNPLVALGAIGEGFHNYHHTFPfdySASEFGLNFNPT--TWF-IDFMCWLG 135
Cdd:PLN02220 203 AIGYHVTWLINSACHIWGSRTWKTKDTSRNVWWLSLFTMGESWHNNHHAFE---SSARQGLEWWQIdiTWYlIRFFEVLG 279


                 ....*....
gi 21732393  136 LATDRKRAT 144
Cdd:PLN02220 280 LATDVKLPT 288
Membrane-FADS-like cd01060
The membrane fatty acid desaturase (Membrane_FADS)-like CD includes membrane FADSs, alkane ...
 66-109 1.22e-05

The membrane fatty acid desaturase (Membrane_FADS)-like CD includes membrane FADSs, alkane hydroxylases, beta carotene ketolases (CrtW-like), hydroxylases (CrtR-like), and other related proteins. They are present in all groups of organisms with the exception of archaea. Membrane FADSs are non-heme, iron-containing, oxygen-dependent enzymes involved in regioselective introduction of double bonds in fatty acyl aliphatic chains. They play an important role in the maintenance of the proper structure and functioning of biological membranes. Alkane hydroxylases are bacterial, integral-membrane di-iron enzymes that share a requirement for iron and oxygen for activity similar to that of membrane FADSs, and are involved in the initial oxidation of inactivated alkanes. Beta-carotene ketolase and beta-carotene hydroxylase are carotenoid biosynthetic enzymes for astaxanthin and zeaxanthin, respectively. This superfamily domain has extensive hydrophobic regions that would be capable of spanning the membrane bilayer at least twice. Comparison of these sequences also reveals three regions of conserved histidine cluster motifs that contain eight histidine residues: HXXX(X)H, HXX(X)HH, and HXXHH (an additional conserved histidine residue is seen between clusters 2 and 3). Spectroscopic and genetic evidence point to a nitrogen-rich coordination environment located in the cytoplasm with as many as eight histidines coordinating the two iron ions and a carboxylate residue bridging the two metals in the Pseudomonas oleovorans alkane hydroxylase (AlkB). In addition, the eight histidine residues are reported to be catalytically essential and proposed to be the ligands for the iron atoms contained within the rat stearoyl CoA delta-9 desaturase.


Pssm-ID: 238511 [Multi-domain]  Cd Length: 122  Bit Score: 42.46  E-value: 1.22e-05
                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 21732393  66 WLVNSAAHMYGNRPYDK-------HISPRQNPLVALGAIGEGFHNYHHTFP 109
Cdd:cd01060  72 SAVNYLEHYGGDRPFDTdgewlrtTDNSRNGWLNLLLTGGLGYHNEHHLFP 122
FA_desaturase pfam00487
Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a ...
 9-109 3.29e-03

Fatty acid desaturase; Fatty acid desaturases are enzymes that catalyze the insertion of a double bond at the delta position of fatty acids. There seem to be two distinct families of fatty acid desaturases which do not seem to be evolutionary related: Family 1 composed of Stearoyl-CoA desaturases (SCD) and Family 2 composed of Bacterial fatty acid desaturases, Plant stearoyl-acyl-carrier-protein desaturase and Cyanobacterial DesA. Members of this entry are ER integral membrane proteins that share the same mushroom-shaped fold consisting of four transmembrane helices (TM1-TM4) which anchor them to the membrane, capped by a cytosolic domain containing a unique 9-10 histidine- coordinating di metal (di-iron) catalytic centre. The structure of mouse stearoyl-CoA desaturase (SDC) revealed that TM2 and TM4 are longer than TM1 and TM3 and protrude into the cytosolic domain, providing three of the nine histidine residues that coordinate the two metal ions, while the other histidine residues are provided by the soluble domain in this enzyme.


Pssm-ID: 425713 [Multi-domain]  Cd Length: 252  Bit Score: 36.56  E-value: 3.29e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 21732393     9 LLADPVVRIQRKYYKISVVLMCFVVPTLVPWYIWGESLWNSYFLASIlryTISLNISWLVNSAAHmYGNRPYDKHISPR- 87
Cdd:pfam00487 122 RKRPIKSRRRRWRLIAWLLLLAAWLGLWLGFLGLGGLLLLLWLLPLL---VFGFLLALIFNYLEH-YGGDWGERPVETTr 197

                          90       100
                  ....*....|....*....|....*.
gi 21732393    88 ----QNPLVALGAIGEGFHNYHHTFP 109
Cdd:pfam00487 198 sirsPNWWLNLLTGNLNYHIEHHLFP 223
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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