Type 2 periplasmic binding fold superfamily; This evolutionary model and hierarchy represent the ligand-binding domains found in solute binding proteins that serve as initial receptors in the transport, signal transduction and channel gating. The PBP2 proteins share the same architecture as periplasmic binding proteins type 1 (PBP1), but have a different topology. They are typically comprised of two globular subdomains connected by a flexible hinge and bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap. The origin of PBP module can be traced across the distant phyla, including eukaryotes, archebacteria, and prokaryotes. The majority of PBP2 proteins are involved in the uptake of a variety of soluble substrates such as phosphate, sulfate, polysaccharides, lysine/arginine/ornithine, and histidine. After binding their specific ligand with high affinity, they can interact with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. Besides transport proteins, the family includes ionotropic glutamate receptors and unorthodox sensor proteins involved in signal transduction. The substrate binding domain of the LysR transcriptional regulators and the oligopeptide-like transport systems also contain the type 2 periplasmic binding fold and thus they are significantly homologous to that of the PBP2; however, these two families are grouped into a separate hierarchy of the PBP2 superfamily due to the large number of protein sequences.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 766451018   1 MLRIDKLACLGCCCFCTVLYICNDEFLKKNPEKVRKFLKAIKKATDYVLADPVKAWKEYIDFKPQLNNDLSY 72
Cdd:cd13650  180 MLRIDKLAELGCCCFCTILYIANDEFLAKNPEKVKKFLRAIKRATDYMLADPVKAWAEYIDFKPQMNTDLNR 251

Substrate binding domain of ABC-type transporters for thiamin biosynthetic pathway intermediates; a member of the type 2 periplasmic binding fold superfamily; ThiY is the periplasmic N-formyl-4-amino-5-(aminomethyl)-2-methylpyrimidine (FAMP) binding component of the ABC transport system (ThiXYZ). FAMP is imported into cell by the transporter, where it is then incorporated into the thiamin biosynthetic pathway. The closest structural homologs of ThiY are periplasmic binding proteins involved in alkanesulfonate/nitrate and bicarbonate transport , as well as THI5 which is responsible for the synthesis of 4-amino-5-(hydroxymethyl)-2-methylpyrimidine phosphate (HMP-P) in the thiamin biosynthetic pathway of eukaryotes. After binding the ligand, they interact with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. The ThiY/THI5 proteins belong to the PBP2 superfamily of periplasmic binding proteins that differ in size and ligand specificity, but have similar tertiary structures consisting of two globular subdomains connected by a flexible hinge. They have been shown to bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 766451018   1 MLRIDKLACLGCCCFCTVLYICNDEFLKKNPEKVRKFLKAIKKATDYVLADPVKAWKEYIDFKPQLNNDLSY 72
Cdd:cd13650  180 MLRIDKLAELGCCCFCTILYIANDEFLAKNPEKVKKFLRAIKRATDYMLADPVKAWAEYIDFKPQMNTDLNR 251

ABC-type nitrate/sulfonate/bicarbonate transport system, periplasmic component [Inorganic ion transport and metabolism];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 766451018  20 YICNDEFLKKNPEKVRKFLKAIKKATDYVLADPVKAWKEYIDFKpQLNNDLSYKQYQRCYAYFSSSLYNVHRDWKKVTGY 99
Cdd:COG0715  208 LVASEDFLEENPEAVKAFLRALLKAWAWAAANPDEAAAILAKAT-GLDPEVLAAALEGDLRLDPPLGAPDPARLQRVADF 286

                         90
                 ....*....|
gi 766451018 100 GKRLAILPPD 109
Cdd:COG0715  287 LVELGLLPKD 296

Substrate binding domain of ABC-type transporters for thiamin biosynthetic pathway intermediates; a member of the type 2 periplasmic binding fold superfamily; ThiY is the periplasmic N-formyl-4-amino-5-(aminomethyl)-2-methylpyrimidine (FAMP) binding component of the ABC transport system (ThiXYZ). FAMP is imported into cell by the transporter, where it is then incorporated into the thiamin biosynthetic pathway. The closest structural homologs of ThiY are periplasmic binding proteins involved in alkanesulfonate/nitrate and bicarbonate transport , as well as THI5 which is responsible for the synthesis of 4-amino-5-(hydroxymethyl)-2-methylpyrimidine phosphate (HMP-P) in the thiamin biosynthetic pathway of eukaryotes. After binding the ligand, they interact with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. The ThiY/THI5 proteins belong to the PBP2 superfamily of periplasmic binding proteins that differ in size and ligand specificity, but have similar tertiary structures consisting of two globular subdomains connected by a flexible hinge. They have been shown to bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 766451018   1 MLRIDKLACLGCCCFCTVLYICNDEFLKKNPEKVRKFLKAIKKATDYVLADPVKAWKEYIDFKPQLNNDLSY 72
Cdd:cd13650  180 MLRIDKLAELGCCCFCTILYIANDEFLAKNPEKVKKFLRAIKRATDYMLADPVKAWAEYIDFKPQMNTDLNR 251

Substrate binding domain of ABC-type transporter for thiamin biosynthetic pathway intermediates and similar proteins; the type 2 periplasmic binding protein fold; ThiY is the periplasmic N-formyl-4-amino-5-(aminomethyl)-2-methylpyrimidine (FAMP) binding component of the ABC transport system (ThiXYZ). FAMP is imported into cell by the transporter, where it is then incorporated into the thiamin biosynthetic pathway. The closest structural homologs of ThiY are THI5, which is responsible for the synthesis of 4-amino-5-(hydroxymethyl)-2-methylpyrimidine phosphate (HMP-P) in the thiamin biosynthetic pathway of eukaryotes, and periplasmic binding proteins involved in alkanesulfonate/nitrate and bicarbonate transport. After binding the ligand, they interact with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. The ThiY/THI5 proteins belong to the PBP2 superfamily of periplasmic binding proteins that differ in size and ligand specificity, but have similar tertiary structures consisting of two globular subdomains connected by a flexible hinge. They have been shown to bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 766451018   1 MLRIDKLAClgcCCFCTVLYICNDEFLKKNPEKVRKFLKAIKKA 44
Cdd:cd13564  174 ASPLVDVAP---GDLTVAMLITNTAYVQQNPEVVKAFQAAIAKA 214

Substrate binding domain of 2'-hydroxybiphenyl-2-sulfinate desulfinase, a member of the type 2 periplasmic binding fold superfamily; This subfamily includes DszB, which converts 2'-hydroxybiphenyl-2-sulfinate to 2-hydroxybiphenyl and sulfinate at the rate-limiting step of the microbial dibenzothiophene desulfurization pathway. The overall fold of DszB is highly similar to those of periplasmic substrate-binding proteins that serve as initial receptors in the ABC transport of bicarbonate, nitrate, taurine, or a wide range of aliphatic sulfonates. After binding their ligand with high affinity, they interact with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. The DszB protein belongs to the PBP2 superfamily of periplasmic binding proteins that differ in size and ligand specificity, but have similar tertiary structures consisting of two globular subdomains connected by a flexible hinge. They have been shown to bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap.

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                 ....*....|....*....|....*....|....
gi 766451018  19 LYICNDEFLKKNPEKVRKFLKAIKKATDYVLADP 52
Cdd:cd13554  191 TWTVRSDFIEQNPEAVKALVEALVRAGDWIQAHP 224

ABC transporter, substrate-binding protein, aliphatic sulfonates family; Members of this family are substrate-binding periplasmic proteins of ABC transporters. This subfamily includes SsuA, a member of a transporter operon needed to obtain sulfur from aliphatic sulfonates. Related proteins outside the scope of this model include taurine (NH2-CH2-CH2-S03H) binding proteins, the probable sulfate ester binding protein AtsR, and the probable aromatic sulfonate binding protein AsfC. All these families make sulfur available when Cys and sulfate levels are low. Please note that phylogenetic analysis by neighbor-joining suggests that a number of sequences belonging to this family have been excluded because of scoring lower than taurine-binding proteins. [Transport and binding proteins, Other]

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                  ....*....|....*....|....*....|....*....|....*..
gi 766451018   17 TVLYICNDEFLKKNPEKVRKFLKAIKKATDYVLADPVKAWKEYIDFK 63
Cdd:TIGR01728 183 PGFLVVRREFAEAHPEQVQRVLKVLVKARKWAEENPEESAKILAKEL 229

Taurine-binding periplasmic protein; the type 2 periplasmic binding protein fold; This subfamily includes the periplasmic component of putative ABC-type sulfonate transport system similar to SsuA. These domains are found in eubacterial SsuA proteins that serve as initial receptors in the ABC transport of bicarbonate, nitrate, taurine, or a wide range of aliphatic sulfonates, while other closest homologs are involved in thiamine (vitamin B1) biosynthetic pathway and desulfurization (DszB). After binding the ligand, SsuA interacts with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. The SsuA proteins belong to the PBP2 superfamily of periplasmic binding proteins that differ in size and ligand specificity, but have similar tertiary structures consisting of two globular subdomains connected by a flexible hinge. They have been shown to bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap.

                         10        20        30
                 ....*....|....*....|....*....|..
gi 766451018  21 ICNDEFLKKNPEKVRKFLKAIKKATDYVLADP 52
Cdd:cd13560  187 VVRKDFAEKYPDVVAAFLKALGDAVDLYRNDP 218