CYSI_ECOBR
ID CYSI_ECOBR Reviewed; 570 AA.
AC C6UCN7;
DT 03-NOV-2009, integrated into UniProtKB/Swiss-Prot.
DT 22-SEP-2009, sequence version 1.
DT 03-AUG-2022, entry version 67.
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=ECB_02608;
OS Escherichia coli (strain B / REL606).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=413997;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=B / REL606;
RX PubMed=19786035; DOI=10.1016/j.jmb.2009.09.052;
RA Jeong H., Barbe V., Lee C.H., Vallenet D., Yu D.S., Choi S.H., Couloux A.,
RA Lee S.W., Yoon S.H., Cattolico L., Hur C.G., Park H.S., Segurens B.,
RA Kim S.C., Oh T.K., Lenski R.E., Studier F.W., Daegelen P., Kim J.F.;
RT "Genome sequences of Escherichia coli B strains REL606 and BL21(DE3).";
RL J. Mol. Biol. 394:644-652(2009).
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; CP000819; ACT40261.1; -; Genomic_DNA.
DR RefSeq; WP_001290699.1; NC_012967.1.
DR AlphaFoldDB; C6UCN7; -.
DR SMR; C6UCN7; -.
DR KEGG; ebr:ECB_02608; -.
DR HOGENOM; CLU_001975_3_2_6; -.
DR OMA; MGMTHGD; -.
DR BioCyc; ECOL413997:GCQD-2830-MON; -.
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..570
FT /note="Sulfite reductase [NADPH] hemoprotein beta-
FT component"
FT /id="PRO_0000388486"
FT BINDING 434
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 440
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 479
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 483
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 483
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 570 AA; 63974 MW; B7B41FEF410DDF04 CRC64;
MSEKHPGPLV VEGKLTDAER MKLESNYLRG TIAEDLNDGL TGGFKGDNFL LIRFHGMYQQ
DDRDIRAERA EQKLEPRHAM LLRCRLPGGV ITTKQWQAID KFAGENTIYG SIRLTNRQTF
QFHGILKKNV KPVHQMLHSV GLDALATAND MNRNVLCTSN PYESQLHAEA YEWAKKISEH
LLPRTRAYAE IWLDQEKVAT TDEEPILGQT YLPRKFKTTV VIPPQNDIDL HANDMNFVAI
AENGKLVGFN LLVGGGLSIE HGNKKTYART ASEFGYLPLE HTLAVAEAVV TTQRDWGNRT
DRKNAKTKYT LERVGVETFK AEVERRAGIK FEPIRPYEFT GRGDRIGWVK GIDDNWHLTL
FIENGRILDY PARPLKTGLL EIAKIHKGDF RITANQNLII AGVPESEKAK IEKIAKESGL
MNAVTPQREN SMACVSFPTC PLAMAEAERF LPSFIDNIDN LMAKHGVSDE HIVMRVTGCP
NGCGRAMLAE VGLVGKAPGR YNLHLGGNRI GTRIPRMYKE NITEPEILAS LDELIGRWAK
EREAGEGFGD FTVRAGIIRP VLDPARDLWD
