CYSI_METSB
ID CYSI_METSB Reviewed; 578 AA.
AC B8EKI5;
DT 03-NOV-2009, integrated into UniProtKB/Swiss-Prot.
DT 03-MAR-2009, sequence version 1.
DT 03-AUG-2022, entry version 75.
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=Msil_2426;
OS Methylocella silvestris (strain DSM 15510 / CIP 108128 / LMG 27833 / NCIMB
OS 13906 / BL2).
OC Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC Beijerinckiaceae; Methylocella.
OX NCBI_TaxID=395965;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=DSM 15510 / CIP 108128 / LMG 27833 / NCIMB 13906 / BL2;
RX PubMed=20472789; DOI=10.1128/jb.00506-10;
RA Chen Y., Crombie A., Rahman M.T., Dedysh S.N., Liesack W., Stott M.B.,
RA Alam M., Theisen A.R., Murrell J.C., Dunfield P.F.;
RT "Complete genome sequence of the aerobic facultative methanotroph
RT Methylocella silvestris BL2.";
RL J. Bacteriol. 192:3840-3841(2010).
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; CP001280; ACK51355.1; -; Genomic_DNA.
DR RefSeq; WP_012591424.1; NC_011666.1.
DR AlphaFoldDB; B8EKI5; -.
DR SMR; B8EKI5; -.
DR STRING; 395965.Msil_2426; -.
DR EnsemblBacteria; ACK51355; ACK51355; Msil_2426.
DR KEGG; msl:Msil_2426; -.
DR eggNOG; COG0155; Bacteria.
DR HOGENOM; CLU_001975_3_2_5; -.
DR OMA; MGMTHGD; -.
DR OrthoDB; 1588103at2; -.
DR UniPathway; UPA00140; UER00207.
DR Proteomes; UP000002257; Chromosome.
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; Reference proteome.
FT CHAIN 1..578
FT /note="Sulfite reductase [NADPH] hemoprotein beta-
FT component"
FT /id="PRO_0000388500"
FT REGION 1..21
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 443
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 449
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 488
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 492
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 492
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 578 AA; 64375 MW; 8885744BD9B0CD95 CRC64;
MTNTLAGPDR SRDISQPLEK LGPDEAMKVR SDYLRGTINE GLLDAITGAV SGDDNAKLMK
FHGVYVQDDR DLRDERRRQK LEPAYSFLIR LRLPGGVATA AQWLKLDELA RAYGNSSLRV
TTRQTFQFHW VLKNDLKATI QGLHEVLIDT IAACGDVVRG VMASVNPSLS SLHAEVYDDA
RRVSEHAMPN MRAYHEIWYG EERVATSEPE EPFLGKQYLP RKFKIGLVIP PYNDIDVYTQ
DLGFIAIAEN GRLIGYNIVI GGGMGRTDQA PETYPRLGDV IGFIPKEQIL AATDAVVGTQ
RDFGDRTVRA HARFKYTIDT HGLDFIQGEI ERRLGYALEP ARPFEFVSNG DAYGWAKGEN
GRYHYTLFIE NGRIVNREDV ALLDGLRAIA AVHQGSFRMT PNQNVVIADI PAKQKPKIAA
LLREYGLDHR NEQSLLRLNS MACVALPTCG LAMAESERYL PTLVTKIETI LAEKGLEKEP
ITIRMTGCPN GCARPYVAEI ALTGRAPGKY NLYFGGGFHG QRLNKMYLEN VGEDAILQAV
DAIAGHYAQD KNPGEHFGDF TIRAGYVKEV RAGREFND
