ID   CYSI_SERP5              Reviewed;         571 AA.
AC   A8G9X7;
DT   05-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT   13-NOV-2007, sequence version 1.
DT   03-AUG-2022, entry version 84.
DE   RecName: Full=Sulfite reductase [NADPH] hemoprotein beta-component {ECO:0000255|HAMAP-Rule:MF_01540};
DE            Short=SiR-HP {ECO:0000255|HAMAP-Rule:MF_01540};
DE            Short=SiRHP {ECO:0000255|HAMAP-Rule:MF_01540};
DE            EC=1.8.1.2 {ECO:0000255|HAMAP-Rule:MF_01540};
GN   Name=cysI {ECO:0000255|HAMAP-Rule:MF_01540}; OrderedLocusNames=Spro_0811;
OS   Serratia proteamaculans (strain 568).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Yersiniaceae; Serratia.
OX   NCBI_TaxID=399741;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=568;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Glavina del Rio T., Dalin E.,
RA   Tice H., Pitluck S., Chain P., Malfatti S., Shin M., Vergez L., Schmutz J.,
RA   Larimer F., Land M., Hauser L., Kyrpides N., Kim E., Taghavi S., Newman L.,
RA   Vangronsveld J., van der Lelie D., Richardson P.;
RT   "Complete sequence of chromosome of Serratia proteamaculans 568.";
RL   Submitted (SEP-2007) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Component of the sulfite reductase complex that catalyzes the
CC       6-electron reduction of sulfite to sulfide. This is one of several
CC       activities required for the biosynthesis of L-cysteine from sulfate.
CC       {ECO:0000255|HAMAP-Rule:MF_01540}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=3 H2O + hydrogen sulfide + 3 NADP(+) = 4 H(+) + 3 NADPH +
CC         sulfite; Xref=Rhea:RHEA:13801, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:17359, ChEBI:CHEBI:29919, ChEBI:CHEBI:57783,
CC         ChEBI:CHEBI:58349; EC=1.8.1.2; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01540};
CC   -!- COFACTOR:
CC       Name=siroheme; Xref=ChEBI:CHEBI:60052;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01540};
CC       Note=Binds 1 siroheme per subunit. {ECO:0000255|HAMAP-Rule:MF_01540};
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01540};
CC       Note=Binds 1 [4Fe-4S] cluster per subunit. {ECO:0000255|HAMAP-
CC       Rule:MF_01540};
CC   -!- PATHWAY: Sulfur metabolism; hydrogen sulfide biosynthesis; hydrogen
CC       sulfide from sulfite (NADPH route): step 1/1. {ECO:0000255|HAMAP-
CC       Rule:MF_01540}.
CC   -!- SUBUNIT: Alpha(8)-beta(8). The alpha component is a flavoprotein, the
CC       beta component is a hemoprotein. {ECO:0000255|HAMAP-Rule:MF_01540}.
CC   -!- SIMILARITY: Belongs to the nitrite and sulfite reductase 4Fe-4S domain
CC       family. {ECO:0000255|HAMAP-Rule:MF_01540}.
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DR   EMBL; CP000826; ABV39917.1; -; Genomic_DNA.
DR   RefSeq; WP_012005259.1; NC_009832.1.
DR   AlphaFoldDB; A8G9X7; -.
DR   SMR; A8G9X7; -.
DR   STRING; 399741.Spro_0811; -.
DR   EnsemblBacteria; ABV39917; ABV39917; Spro_0811.
DR   KEGG; spe:Spro_0811; -.
DR   eggNOG; COG0155; Bacteria.
DR   HOGENOM; CLU_001975_3_2_6; -.
DR   OMA; MGMTHGD; -.
DR   OrthoDB; 1588103at2; -.
DR   UniPathway; UPA00140; UER00207.
DR   GO; GO:0009337; C:sulfite reductase complex (NADPH); IEA:InterPro.
DR   GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-KW.
DR   GO; GO:0020037; F:heme binding; IEA:InterPro.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0050661; F:NADP binding; IEA:InterPro.
DR   GO; GO:0004783; F:sulfite reductase (NADPH) activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0019344; P:cysteine biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0070814; P:hydrogen sulfide biosynthetic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0000103; P:sulfate assimilation; IEA:UniProtKB-UniRule.
DR   Gene3D; 3.30.413.10; -; 2.
DR   HAMAP; MF_01540; CysI; 1.
DR   InterPro; IPR011786; CysI.
DR   InterPro; IPR005117; NiRdtase/SiRdtase_haem-b_fer.
DR   InterPro; IPR036136; Nit/Sulf_reduc_fer-like_dom_sf.
DR   InterPro; IPR006067; NO2/SO3_Rdtase_4Fe4S_dom.
DR   InterPro; IPR045169; NO2/SO3_Rdtase_4Fe4S_prot.
DR   InterPro; IPR045854; NO2/SO3_Rdtase_4Fe4S_sf.
DR   InterPro; IPR006066; NO2/SO3_Rdtase_FeS/sirohaem_BS.
DR   PANTHER; PTHR11493; PTHR11493; 1.
DR   Pfam; PF01077; NIR_SIR; 2.
DR   Pfam; PF03460; NIR_SIR_ferr; 2.
DR   PRINTS; PR00397; SIROHAEM.
DR   SUPFAM; SSF55124; SSF55124; 2.
DR   SUPFAM; SSF56014; SSF56014; 2.
DR   TIGRFAMs; TIGR02041; CysI; 1.
DR   PROSITE; PS00365; NIR_SIR; 1.
PE   3: Inferred from homology;
KW   4Fe-4S; Amino-acid biosynthesis; Cysteine biosynthesis; Heme; Iron;
KW   Iron-sulfur; Metal-binding; NADP; Oxidoreductase.
FT   CHAIN           1..571
FT                   /note="Sulfite reductase [NADPH] hemoprotein beta-
FT                   component"
FT                   /id="PRO_1000068767"
FT   BINDING         435
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT   BINDING         441
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT   BINDING         480
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT   BINDING         484
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT   BINDING         484
FT                   /ligand="siroheme"
FT                   /ligand_id="ChEBI:CHEBI:60052"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
SQ   SEQUENCE   571 AA;  63873 MW;  805C43AF6C8F21AE CRC64;
     MSDKHPGPLV VEGKLADAER LKKESNFLRG TIAEDLKDGL TGGFTGDNFL LIRFHGMYQQ
     DDRDIRAERA EQKLEPRHAM MLRCRLPGGI ISPQQWLGID KFAQESTLYG SIRITNRQTF
     QFHGILKGNV KPVHQLLGRL GLDALATAND VNRNVLCTSN PVESELHQEA YEWAKKISEH
     LLPRTRAYAE VWLDQEKVAT TDEEPILGAT YLPRKFKTTV VIPPQNDVDL HANDMNFVAI
     AKNGKLVGFN LLVGGGLSIE HGNKKTYARQ ASEFGYIPLE HTLAVAEAVV TTQRDWGNRT
     DRKNAKTKYT LERVGVDTFR AEVEKRAGIT FEPIRPYEFT GRGDRIGWVK GIDNQWHLTL
     FIENGRLLDY PGRPLKTGVA EIARIHKGDF RLTANQNLIV AGVPESEKAK IEALARDHGL
     IDDGVSVQRQ NSMACVSFPT CPLAMAEAER FLPEFVTKVE GILHRHGVGD EHIVLRITGC
     PNGCGRALLA EIGLVGKAVG RYNLHLGGNR EGTRIPRMYR ENINEEEILR EIDQLVGRWA
     TERTAGEGFG DFTIRAGVVR PVVDPAQDFW D