CYSI_BUCAI
ID CYSI_BUCAI Reviewed; 569 AA.
AC P57502;
DT 01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-DEC-2000, sequence version 1.
DT 03-AUG-2022, entry version 117.
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=BU427;
OS Buchnera aphidicola subsp. Acyrthosiphon pisum (strain APS) (Acyrthosiphon
OS pisum symbiotic bacterium).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Erwiniaceae; Buchnera.
OX NCBI_TaxID=107806;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=APS;
RX PubMed=10993077; DOI=10.1038/35024074;
RA Shigenobu S., Watanabe H., Hattori M., Sakaki Y., Ishikawa H.;
RT "Genome sequence of the endocellular bacterial symbiont of aphids Buchnera
RT sp. APS.";
RL Nature 407:81-86(2000).
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; BA000003; BAB13125.1; -; Genomic_DNA.
DR RefSeq; NP_240239.1; NC_002528.1.
DR RefSeq; WP_009874380.1; NC_002528.1.
DR AlphaFoldDB; P57502; -.
DR SMR; P57502; -.
DR STRING; 107806.10039091; -.
DR EnsemblBacteria; BAB13125; BAB13125; BAB13125.
DR KEGG; buc:BU427; -.
DR PATRIC; fig|107806.10.peg.436; -.
DR eggNOG; COG0155; Bacteria.
DR HOGENOM; CLU_001975_3_2_6; -.
DR OMA; MGMTHGD; -.
DR UniPathway; UPA00140; UER00207.
DR Proteomes; UP000001806; 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..569
FT /note="Sulfite reductase [NADPH] hemoprotein beta-
FT component"
FT /id="PRO_0000199893"
FT BINDING 433
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 439
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 478
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 482
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01540"
FT BINDING 482
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 569 AA; 65742 MW; 7CC09375A08B8DAB CRC64;
MNKKFKKIVT EKKLTDAERI KENSNYLRGT ITDDLKNEIT NGFTGDNFSL IRFHGMYQQD
DRDLRIERNE QKLEPRYAMM LRCRLPGGVI KAKKWLKIDY FASKYTLYGT IRLTNRQTFQ
FHGILKKNLK DVHKMLHSIG LDSLATANDV NRNVLCTSNP MESLIHQEAY EWARKISNFL
LPHTKAYAEI WLDQKKIVTT EKEPILGKTY LPRKFKTTVV IPPYNDVDLY ANDMNFVAIT
KNEKIIGFNI LIGGGLSFIH GNKNTWPFLA TEIGYISVEN TLSIAKAIVT TQRDWGNRTD
RANAKTRYTI NNFGLNEFKK EIEKRANVNL KPVREYSFIS RGDRFGWIKD INNNWSLTLF
IQNGRIYDDN DKLFKSGLLK IANIHDGNFR ITSNQNIIIS EVSEKNKNKI EKIALSSGLI
NKSTNLRKNS MACVSFPTCP LAMAEAERML SFFITQLENI MLKYGVEDEV IILRVSGCPN
GCGRSLLAEI GLIGKSIGRY NLYIGGNRIG NRIPKIYKEN ITEQEILIHL KYLIKTWSNE
RKNKEDFGDF IVRKEFVKEV INPVYDFWS
