ID   MBHT_ECOLI              Reviewed;         372 AA.
AC   P69741; Q2M9J8; Q46847;
DT   26-APR-2005, integrated into UniProtKB/Swiss-Prot.
DT   26-APR-2005, sequence version 1.
DT   02-SEP-2026, entry version 151.
DE   RecName: Full=Hydrogenase-2 small chain;
DE            Short=HYD2;
DE            EC=1.12.99.6;
DE   AltName: Full=Membrane-bound hydrogenase 2 small subunit;
DE   AltName: Full=NiFe hydrogenase;
DE   Flags: Precursor;
GN   Name=hybO; Synonyms=yghV; OrderedLocusNames=b2997, JW2965;
OS   Escherichia coli (strain K12).
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=83333;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=9278503; DOI=10.1126/science.277.5331.1453;
RA   Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V.,
RA   Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F.,
RA   Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B.,
RA   Shao Y.;
RT   "The complete genome sequence of Escherichia coli K-12.";
RL   Science 277:1453-1462(1997).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX   PubMed=16738553; DOI=10.1038/msb4100049;
RA   Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S.,
RA   Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.;
RT   "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655
RT   and W3110.";
RL   Mol. Syst. Biol. 2:E1-E5(2006).
RN   [3]
RP   PROTEIN SEQUENCE OF 38-47 AND 218-234, CHARACTERIZATION, AND EXPORT VIA THE
RP   TAT-SYSTEM.
RC   STRAIN=K12 / MC4100 / ATCC 35695 / DSM 6574;
RX   PubMed=9738917; DOI=10.1046/j.1432-1327.1998.2550746.x;
RA   Sargent F., Ballantine S.P., Rugman P.A., Palmer T., Boxer D.H.;
RT   "Reassignment of the gene encoding the Escherichia coli hydrogenase 2 small
RT   subunit -- identification of a soluble precursor of the small subunit in a
RT   hypB mutant.";
RL   Eur. J. Biochem. 255:746-754(1998).
RN   [4]
RP   EXPORT VIA THE TAT-SYSTEM AND THE SEC-SYSTEM.
RX   PubMed=17218314; DOI=10.1074/jbc.m610507200;
RA   Tullman-Ercek D., DeLisa M.P., Kawarasaki Y., Iranpour P., Ribnicky B.,
RA   Palmer T., Georgiou G.;
RT   "Export pathway selectivity of Escherichia coli twin arginine translocation
RT   signal peptides.";
RL   J. Biol. Chem. 282:8309-8316(2007).
CC   -!- FUNCTION: This is one of three E.coli hydrogenases synthesized in
CC       response to different physiological conditions. HYD2 is involved in
CC       hydrogen uptake.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H2 + A = AH2; Xref=Rhea:RHEA:12116, ChEBI:CHEBI:13193,
CC         ChEBI:CHEBI:17499, ChEBI:CHEBI:18276; EC=1.12.99.6;
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC         Evidence={ECO:0000250|UniProtKB:P21853};
CC       Note=Binds 2 [4Fe-4S] clusters. {ECO:0000250|UniProtKB:P21853};
CC   -!- COFACTOR:
CC       Name=[3Fe-4S] cluster; Xref=ChEBI:CHEBI:21137;
CC         Evidence={ECO:0000250|UniProtKB:P21853};
CC       Note=Binds 1 [3Fe-4S] cluster. {ECO:0000250|UniProtKB:P21853};
CC   -!- SUBUNIT: Heterodimer of a large and a small subunit.
CC   -!- INTERACTION:
CC       P69741; P0AAN1: hybE; NbExp=6; IntAct=EBI-552619, EBI-552588;
CC   -!- SUBCELLULAR LOCATION: Cell membrane; Peripheral membrane protein;
CC       Periplasmic side. Periplasm.
CC   -!- PTM: Exported by the Tat system. The position of the signal peptide
CC       cleavage has been experimentally proven. Can also be exported by the
CC       Sec system.
CC   -!- SIMILARITY: Belongs to the [NiFe]/[NiFeSe] hydrogenase small subunit
CC       family. {ECO:0000305}.
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DR   EMBL; U28377; AAA69164.1; -; Genomic_DNA.
DR   EMBL; U00096; AAC76033.1; -; Genomic_DNA.
DR   EMBL; AP009048; BAE77058.1; -; Genomic_DNA.
DR   PIR; C65086; C65086.
DR   RefSeq; NP_417471.1; NC_000913.3.
DR   RefSeq; WP_000145410.1; NZ_CP009789.1.
DR   PDB; 6EHQ; X-ray; 2.20 A; S/T=38-330.
DR   PDB; 6EHS; X-ray; 1.50 A; S/T=38-330.
DR   PDB; 6EN9; X-ray; 1.50 A; S/T=39-331.
DR   PDB; 6G7M; X-ray; 1.71 A; S/T=38-333.
DR   PDB; 6GAM; X-ray; 1.40 A; S/T=38-330.
DR   PDB; 6GAN; X-ray; 1.60 A; S/T=38-330.
DR   PDB; 6SYO; X-ray; 1.25 A; SSS/TTT=39-331.
DR   PDB; 6SYX; X-ray; 1.30 A; SSS/TTT=39-330.
DR   PDB; 6SZD; X-ray; 1.50 A; SSS/TTT=39-330.
DR   PDB; 6SZK; X-ray; 1.20 A; SSS/TTT=39-330.
DR   PDB; 7NEM; X-ray; 1.35 A; S/T=39-330.
DR   PDB; 9ERB; X-ray; 1.30 A; S/T=39-330.
DR   PDB; 9ERC; X-ray; 1.31 A; S/T=39-330.
DR   PDB; 9ERP; X-ray; 1.37 A; S/T=39-330.
DR   PDB; 9ERR; X-ray; 1.40 A; S/T=39-330.
DR   PDB; 9ERS; X-ray; 1.59 A; S/T=39-330.
DR   AlphaFoldDB; P69741; -.
DR   SMR; P69741; -.
DR   BioGRID; 4261299; 264.
DR   BioGRID; 850267; 10.
DR   ComplexPortal; CPX-282; Hydrogenase-2 complex.
DR   DIP; DIP-36024N; -.
DR   FunCoup; P69741; 274.
DR   IntAct; P69741; 17.
DR   MINT; P69741; -.
DR   STRING; 511145.b2997; -.
DR   TCDB; 3.D.7.2.5; the h2:heterodisulfide oxidoreductase (hho) family.
DR   jPOST; P69741; -.
DR   PaxDb; 511145-b2997; -.
DR   EnsemblBacteria; AAC76033; AAC76033; b2997.
DR   GeneID; 67175472; -.
DR   GeneID; 93778988; -.
DR   GeneID; 945902; -.
DR   KEGG; ecj:JW2965; -.
DR   KEGG; eco:b2997; -.
DR   KEGG; ecoc:C3026_16390; -.
DR   PATRIC; fig|1411691.4.peg.3732; -.
DR   EchoBASE; EB2828; -.
DR   eggNOG; COG1740; Bacteria.
DR   HOGENOM; CLU_046107_0_1_6; -.
DR   InParanoid; P69741; -.
DR   OMA; VPGCPIQ; -.
DR   OrthoDB; 9766729at2; -.
DR   PhylomeDB; P69741; -.
DR   BioCyc; EcoCyc:MONOMER0-145; -.
DR   BioCyc; MetaCyc:MONOMER0-145; -.
DR   BRENDA; 1.12.99.6; 2026.
DR   PHI-base; PHI:10996; -.
DR   PRO; PR:P69741; -.
DR   Proteomes; UP000000625; Chromosome.
DR   AbasyAtlas; P69741; -.
DR   GO; GO:0044569; C:[Ni-Fe] hydrogenase complex; IBA:GO_Central.
DR   GO; GO:0009375; C:ferredoxin hydrogenase complex; IEA:InterPro.
DR   GO; GO:0016020; C:membrane; HDA:UniProtKB.
DR   GO; GO:0042597; C:periplasmic space; IEA:UniProtKB-SubCell.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0009055; F:electron transfer activity; IBA:GO_Central.
DR   GO; GO:0008901; F:ferredoxin hydrogenase activity; IEA:InterPro.
DR   GO; GO:0033748; F:hydrogenase (acceptor) activity; IEA:UniProtKB-EC.
DR   GO; GO:0051536; F:iron-sulfur cluster binding; ISM:EcoCyc.
DR   GO; GO:0009061; P:anaerobic respiration; EXP:EcoCyc.
DR   FunFam; 3.40.50.700:FF:000001; Hydrogenase 2 small subunit; 1.
DR   FunFam; 4.10.480.10:FF:000001; Hydrogenase 2 small subunit; 1.
DR   Gene3D; 4.10.480.10; Cytochrome-c3 hydrogenase, C-terminal domain; 1.
DR   Gene3D; 3.40.50.700; NADH:ubiquinone oxidoreductase-like, 20kDa subunit; 1.
DR   InterPro; IPR027394; Cytochrome-c3_hydrogenase_C.
DR   InterPro; IPR006137; NADH_UbQ_OxRdtase-like_20kDa.
DR   InterPro; IPR037148; NiFe-Hase_small_C_sf.
DR   InterPro; IPR037024; NiFe_Hase_small_N_sf.
DR   InterPro; IPR001821; NiFe_hydrogenase_ssu.
DR   InterPro; IPR006311; TAT_signal.
DR   InterPro; IPR019546; TAT_signal_bac_arc.
DR   NCBIfam; TIGR00391; hydA; 1.
DR   NCBIfam; NF007779; PRK10468.1; 1.
DR   NCBIfam; TIGR01409; TAT_signal_seq; 1.
DR   PANTHER; PTHR30013:SF7; HYDROGENASE-2 SMALL CHAIN; 1.
DR   PANTHER; PTHR30013; NIFE / NIFESE HYDROGENASE SMALL SUBUNIT FAMILY MEMBER; 1.
DR   Pfam; PF14720; NiFe_hyd_SSU_C; 1.
DR   Pfam; PF01058; Oxidored_q6; 1.
DR   PIRSF; PIRSF000310; NiFe_hyd_ssu; 1.
DR   PRINTS; PR00614; NIHGNASESMLL.
DR   SUPFAM; SSF56770; HydA/Nqo6-like; 1.
DR   PROSITE; PS51318; TAT; 1.
DR   PDBsum; 6EHQ; -.
DR   PDBsum; 6EHS; -.
DR   PDBsum; 6EN9; -.
DR   PDBsum; 6G7M; -.
DR   PDBsum; 6GAM; -.
DR   PDBsum; 6GAN; -.
DR   PDBsum; 6SYO; -.
DR   PDBsum; 6SYX; -.
DR   PDBsum; 6SZD; -.
DR   PDBsum; 6SZK; -.
DR   PDBsum; 7NEM; -.
DR   PDBsum; 9ERB; -.
DR   PDBsum; 9ERC; -.
DR   PDBsum; 9ERP; -.
DR   PDBsum; 9ERR; -.
DR   PDBsum; 9ERS; -.
PE   1: Evidence at protein level;
KW   3D-structure; 3Fe-4S; 4Fe-4S; Cell membrane; Direct protein sequencing;
KW   Iron; Iron-sulfur; Membrane; Metal-binding; Oxidoreductase; Periplasm;
KW   Reference proteome; Signal.
FT   SIGNAL          1..37
FT                   /note="Tat-type signal"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00648,
FT                   ECO:0000269|PubMed:9738917"
FT   CHAIN           38..372
FT                   /note="Hydrogenase-2 small chain"
FT                   /id="PRO_0000013430"
FT   BINDING         59
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         62
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         157
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         191
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         229
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         232
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         257
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         263
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         272
FT                   /ligand="[3Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21137"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         292
FT                   /ligand="[3Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21137"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   BINDING         295
FT                   /ligand="[3Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21137"
FT                   /evidence="ECO:0000250|UniProtKB:P21853"
FT   HELIX           47..49
FT                   /evidence="ECO:0007829|PDB:6SZD"
FT   STRAND          50..57
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           61..65
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           66..68
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           77..81
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          83..86
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   TURN            88..90
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           95..108
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   TURN            109..112
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          114..122
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           124..127
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          130..132
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           137..146
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          149..155
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           156..160
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           162..165
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           176..179
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          185..188
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          190..192
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           195..208
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           211..213
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           221..224
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          225..227
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           228..231
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           235..240
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           252..254
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           259..261
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           265..267
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          269..271
FT                   /evidence="ECO:0007829|PDB:6SYX"
FT   TURN            272..275
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   STRAND          280..282
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           285..288
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   TURN            298..303
FT                   /evidence="ECO:0007829|PDB:6SZK"
FT   HELIX           309..311
FT                   /evidence="ECO:0007829|PDB:6SZK"
SQ   SEQUENCE   372 AA;  39652 MW;  C5821096BBAF9C66 CRC64;
     MTGDNTLIHS HGINRRDFMK LCAALAATMG LSSKAAAEMA ESVTNPQRPP VIWIGAQECT
     GCTESLLRAT HPTVENLVLE TISLEYHEVL SAAFGHQVEE NKHNALEKYK GQYVLVVDGS
     IPLKDNGIYC MVAGEPIVDH IRKAAEGAAA IIAIGSCSAW GGVAAAGVNP TGAVSLQEVL
     PGKTVINIPG CPPNPHNFLA TVAHIITYGK PPKLDDKNRP TFAYGRLIHE HCERRPHFDA
     GRFAKEFGDE GHREGWCLYH LGCKGPETYG NCSTLQFCDV GGVWPVAIGH PCYGCNEEGI
     GFHKGIHQLA NVENQTPRSQ KPDVNAKEGG NVSAGAIGLL GGVVGLVAGV SVMAVRELGR
     QQKKDNADSR GE
//