ID   MCRB_METFE              Reviewed;         438 AA.
AC   P12972;
DT   01-OCT-1989, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1989, sequence version 1.
DT   03-AUG-2022, entry version 93.
DE   RecName: Full=Methyl-coenzyme M reductase subunit beta;
DE            EC=2.8.4.1 {ECO:0000250|UniProtKB:P11560};
DE   AltName: Full=Coenzyme-B sulfoethylthiotransferase beta;
GN   Name=mcrB;
OS   Methanothermus fervidus.
OC   Archaea; Euryarchaeota; Methanomada group; Methanobacteria;
OC   Methanobacteriales; Methanothermaceae; Methanothermus.
OX   NCBI_TaxID=2180;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=3170483; DOI=10.1128/jb.170.10.4718-4726.1988;
RA   Weil C.F., Cram D.S., Sherf B.A., Reeve J.N.;
RT   "Structure and comparative analysis of the genes encoding component C of
RT   methyl coenzyme M reductase in the extremely thermophilic archaebacterium
RT   Methanothermus fervidus.";
RL   J. Bacteriol. 170:4718-4726(1988).
CC   -!- FUNCTION: Component of the methyl-coenzyme M reductase (MCR) I that
CC       catalyzes the reductive cleavage of methyl-coenzyme M (CoM-S-CH3 or 2-
CC       (methylthio)ethanesulfonate) using coenzyme B (CoB or 7-
CC       mercaptoheptanoylthreonine phosphate) as reductant which results in the
CC       production of methane and the mixed heterodisulfide of CoB and CoM
CC       (CoM-S-S-CoB). This is the final step in methanogenesis.
CC       {ECO:0000250|UniProtKB:P11560}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=coenzyme B + methyl-coenzyme M = coenzyme M-coenzyme B
CC         heterodisulfide + methane; Xref=Rhea:RHEA:12532, ChEBI:CHEBI:16183,
CC         ChEBI:CHEBI:58286, ChEBI:CHEBI:58411, ChEBI:CHEBI:58596; EC=2.8.4.1;
CC         Evidence={ECO:0000250|UniProtKB:P11560};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:12533;
CC         Evidence={ECO:0000250|UniProtKB:P11560};
CC   -!- COFACTOR:
CC       Name=coenzyme F430; Xref=ChEBI:CHEBI:60540;
CC         Evidence={ECO:0000250|UniProtKB:P11560};
CC       Note=Binds 2 coenzyme F430 non-covalently per MCR complex. Coenzyme
CC       F430 is a yellow nickel porphinoid. Methyl-coenzyme-M reductase is
CC       activated when the enzyme-bound coenzyme F430 is reduced to the Ni(I)
CC       oxidation state. {ECO:0000250|UniProtKB:P11560};
CC   -!- PATHWAY: One-carbon metabolism; methyl-coenzyme M reduction; methane
CC       from methyl-coenzyme M: step 1/1. {ECO:0000250|UniProtKB:P11560}.
CC   -!- SUBUNIT: MCR is a hexamer of two alpha, two beta, and two gamma chains,
CC       forming a dimer of heterotrimers. {ECO:0000250|UniProtKB:P11560}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P11560}.
CC   -!- SIMILARITY: Belongs to the methyl-coenzyme M reductase beta subunit
CC       family. {ECO:0000305}.
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DR   EMBL; J03375; AAA72193.1; -; Genomic_DNA.
DR   AlphaFoldDB; P12972; -.
DR   SMR; P12972; -.
DR   UniPathway; UPA00646; UER00699.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0050524; F:coenzyme-B sulfoethylthiotransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0015948; P:methanogenesis; IEA:UniProtKB-KW.
DR   Gene3D; 1.20.840.10; -; 1.
DR   Gene3D; 3.30.70.470; -; 1.
DR   InterPro; IPR008924; Me_CoM_Rdtase_asu/bsu_C.
DR   InterPro; IPR015823; Me_CoM_Rdtase_asu_N_sub2.
DR   InterPro; IPR003179; Me_CoM_Rdtase_bsu.
DR   InterPro; IPR022679; Me_CoM_Rdtase_bsu_C.
DR   InterPro; IPR022680; Me_CoM_Rdtase_bsu_N.
DR   InterPro; IPR009024; Me_CoM_Rdtase_Fd-like_fold.
DR   Pfam; PF02241; MCR_beta; 1.
DR   Pfam; PF02783; MCR_beta_N; 1.
DR   PIRSF; PIRSF000263; Meth_CoM_rd_beta; 1.
DR   SUPFAM; SSF48081; SSF48081; 1.
DR   SUPFAM; SSF55088; SSF55088; 1.
DR   TIGRFAMs; TIGR03257; met_CoM_red_bet; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Methanogenesis; Transferase.
FT   CHAIN           1..438
FT                   /note="Methyl-coenzyme M reductase subunit beta"
FT                   /id="PRO_0000147463"
FT   BINDING         367
FT                   /ligand="coenzyme M"
FT                   /ligand_id="ChEBI:CHEBI:58319"
FT                   /evidence="ECO:0000250|UniProtKB:P11560"
FT   BINDING         369
FT                   /ligand="coenzyme B"
FT                   /ligand_id="ChEBI:CHEBI:58596"
FT                   /evidence="ECO:0000250|UniProtKB:P11560"
SQ   SEQUENCE   438 AA;  47034 MW;  76E0EE0DCB8CEC75 CRC64;
     MPKYEDKVDL YDDRGNLVEE QVPIEALSPL RNTAIKKIIH DIKRTVAVNL EGIENALRSA
     KVGGSGCHIP GRELDVDVID NAEAIAEKAK EMIQVEEGDD TVVELLHDGK RALVKVPSSR
     LESAAEYSVA PLVTASAFIQ SIIDVCDISI YDANMVKAAV LGRYPQSVEY VGGNIATMLD
     IPQKLEGPGY ALRNILVNHI VAATLKNTLQ AVALSSILEH TAMFEMGDAV GKFERLHLLG
     LAYQGLNADN LLYDLVKANG KDGTVGSVVE DVVERAKEDG VIKVEKELNG YKVYGTDDLA
     LWNAYAAAGL VAATIVNQGA ARAAQGVSST ILYDNDIIEF ERGLPGVDFG RAEGTAVGFS
     FFSHSIYGGG GPGIFNGNHI VTRHSKGFAI PCVAAAMALD AGTQMFSPEL TSGLIKDVFS
     KVDEFREPLK YVVELQPK