ID   MCRB_METVO              Reviewed;         443 AA.
AC   P11561;
DT   01-OCT-1989, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1989, sequence version 1.
DT   03-AUG-2022, entry version 94.
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   Methanococcus voltae.
OC   Archaea; Euryarchaeota; Methanomada group; Methanococci; Methanococcales;
OC   Methanococcaceae; Methanococcus.
OX   NCBI_TaxID=2188;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 33273 / DSM 1537 / NBRC 100457 / OCM 70 / PS;
RX   PubMed=3185509; DOI=10.1007/bf00339610;
RA   Klein A., Allmansberger R., Bokranz M., Knaub S., Mueller B., Muth E.;
RT   "Comparative analysis of genes encoding methyl coenzyme M reductase in
RT   methanogenic bacteria.";
RL   Mol. Gen. Genet. 213:409-420(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; X07793; CAA30630.1; -; Genomic_DNA.
DR   PIR; S03257; S03257.
DR   AlphaFoldDB; P11561; -.
DR   SMR; P11561; -.
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..443
FT                   /note="Methyl-coenzyme M reductase subunit beta"
FT                   /id="PRO_0000147472"
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   443 AA;  46681 MW;  E9E545ED9E48AB3F CRC64;
     MVKYEDKICL FDAKGNQVAE DVPLEAISPL NNPTIMGMVK NIKRTVAVNL AGIEESLAKG
     KIGGKGCQVP GTNIELDVIG DAEAIADKVK SILQVSAGDD TEVKLINGGK QMAEQVPSKR
     LDVAAEYSVS MLSTGMALKE ALITNFNIDM FDGSTVHSAI MGQYPQDMDY AGGNIASLLG
     APSKLEGLGY ALRNIPVNHA VATTKKSLMN AIAFSSILEQ TAMFEMGDAV GSFERQHLLG
     LAYQGLNADN LVVELVKANA TGTVGSVVNS IVEKAIADGV IVVDKTLGSG FNMYKPADVN
     KWNAYAAAGL VAAVMVSCGA ARAAQNVAST ILYYNDILEY ETGLPGVDYG RSMGTAVGFS
     FFSHSIYGGG GPGIFNGNHV VTRHSKGFAI PPVCAAMCMD AGTQMFSPEK TSALVGTVYS
     AFDEFREPLK YVIEGALEVQ NKL