ID   MCRX_METTH              Reviewed;         553 AA.
AC   P21110; O27201; Q50487;
DT   01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT   30-MAY-2000, sequence version 3.
DT   27-MAR-2024, entry version 142.
DE   RecName: Full=Methyl-coenzyme M reductase II subunit alpha {ECO:0000303|PubMed:2269306};
DE            Short=MCR II alpha {ECO:0000303|PubMed:2269306};
DE            EC=2.8.4.1 {ECO:0000269|PubMed:2269306};
DE   AltName: Full=Coenzyme-B sulfoethylthiotransferase alpha;
GN   Name=mrtA; OrderedLocusNames=MTH_1129;
OS   Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM
OS   10044 / NBRC 100330 / Delta H) (Methanobacterium thermoautotrophicum).
OC   Archaea; Euryarchaeota; Methanomada group; Methanobacteria;
OC   Methanobacteriales; Methanobacteriaceae; Methanothermobacter.
OX   NCBI_TaxID=187420;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H;
RX   PubMed=7929010; DOI=10.1128/jb.176.20.6384-6391.1994;
RA   Pihl T.D., Sharma S., Reeve J.N.;
RT   "Growth phase-dependent transcription of the genes that encode the two
RT   methyl coenzyme M reductase isoenzymes and N5-
RT   methyltetrahydromethanopterin:coenzyme M methyltransferase in
RT   Methanobacterium thermoautotrophicum delta H.";
RL   J. Bacteriol. 176:6384-6391(1994).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H;
RX   PubMed=9371463; DOI=10.1128/jb.179.22.7135-7155.1997;
RA   Smith D.R., Doucette-Stamm L.A., Deloughery C., Lee H.-M., Dubois J.,
RA   Aldredge T., Bashirzadeh R., Blakely D., Cook R., Gilbert K., Harrison D.,
RA   Hoang L., Keagle P., Lumm W., Pothier B., Qiu D., Spadafora R., Vicare R.,
RA   Wang Y., Wierzbowski J., Gibson R., Jiwani N., Caruso A., Bush D.,
RA   Safer H., Patwell D., Prabhakar S., McDougall S., Shimer G., Goyal A.,
RA   Pietrovski S., Church G.M., Daniels C.J., Mao J.-I., Rice P., Noelling J.,
RA   Reeve J.N.;
RT   "Complete genome sequence of Methanobacterium thermoautotrophicum deltaH:
RT   functional analysis and comparative genomics.";
RL   J. Bacteriol. 179:7135-7155(1997).
RN   [3]
RP   PROTEIN SEQUENCE OF 1-15, FUNCTION, CATALYTIC ACTIVITY, AND SUBUNIT.
RC   STRAIN=ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H;
RX   PubMed=2269306; DOI=10.1111/j.1432-1033.1990.tb19481.x;
RA   Rospert S., Linder D., Ellermann J., Thauer R.K.;
RT   "Two genetically distinct methyl-coenzyme M reductases in Methanobacterium
RT   thermoautotrophicum strain Marburg and delta H.";
RL   Eur. J. Biochem. 194:871-877(1990).
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:0000269|PubMed:2269306}.
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:0000269|PubMed:2269306};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:12533;
CC         Evidence={ECO:0000305|PubMed:2269306};
CC   -!- COFACTOR:
CC       Name=coenzyme F430; Xref=ChEBI:CHEBI:60540;
CC         Evidence={ECO:0000250|UniProtKB:P11558};
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:P11558};
CC   -!- PATHWAY: One-carbon metabolism; methyl-coenzyme M reduction; methane
CC       from methyl-coenzyme M: step 1/1. {ECO:0000305|PubMed:2269306}.
CC   -!- SUBUNIT: MCR is a hexamer of two alpha, two beta, and two gamma chains,
CC       forming a dimer of heterotrimers. {ECO:0000269|PubMed:2269306}.
CC   -!- DEVELOPMENTAL STAGE: There are two MCR complexes in this bacteria. MCR
CC       II is expressed in the early growth phase. Late growth cells contain
CC       mostly MCR I. {ECO:0000250|UniProtKB:P11558}.
CC   -!- PTM: The alpha subunit contains six modified amino acids near the
CC       active site region. Is methylated on His-260, Arg-274, Gln-402 and Cys-
CC       454, probably by the action of specific S-adenosylmethionine-dependent
CC       methyltransferases. Also contains a thioglycine at position 447,
CC       forming a thiopeptide bond. Contains a didehydroaspartate residue at
CC       position 452 (By similarity). The methylation on C5 of Arg-274 is a
CC       post-translational methylation not essential in vivo, but which plays a
CC       role for the stability and structural integrity of MCR (By similarity).
CC       {ECO:0000250|UniProtKB:P58815, ECO:0000250|UniProtKB:Q8THH1}.
CC   -!- SIMILARITY: Belongs to the methyl-coenzyme M reductase alpha subunit
CC       family. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; U09990; AAA73439.1; -; Genomic_DNA.
DR   EMBL; AE000666; AAB85618.1; -; Genomic_DNA.
DR   PIR; C69017; C69017.
DR   PIR; T45150; T45150.
DR   RefSeq; WP_010876753.1; NC_000916.1.
DR   AlphaFoldDB; P21110; -.
DR   SMR; P21110; -.
DR   IntAct; P21110; 2.
DR   STRING; 187420.MTH_1129; -.
DR   PaxDb; 187420-MTH_1129; -.
DR   EnsemblBacteria; AAB85618; AAB85618; MTH_1129.
DR   GeneID; 1471537; -.
DR   KEGG; mth:MTH_1129; -.
DR   PATRIC; fig|187420.15.peg.1106; -.
DR   HOGENOM; CLU_493170_0_0_2; -.
DR   InParanoid; P21110; -.
DR   BioCyc; MetaCyc:MRTAMAUTO-MONOMER; -.
DR   UniPathway; UPA00646; UER00699.
DR   Proteomes; UP000005223; Chromosome.
DR   GO; GO:0050524; F:coenzyme-B sulfoethylthiotransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0015948; P:methanogenesis; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.70.470; -; 1.
DR   Gene3D; 1.20.840.10; Methyl-coenzyme M reductase, alpha/beta subunit, C-terminal; 1.
DR   InterPro; IPR016212; Me_CoM_Rdtase_asu.
DR   InterPro; IPR008924; Me_CoM_Rdtase_asu/bsu_C.
DR   InterPro; IPR009047; Me_CoM_Rdtase_asu_C.
DR   InterPro; IPR003183; Me_CoM_Rdtase_asu_N.
DR   InterPro; IPR015811; Me_CoM_Rdtase_asu_N_sub1.
DR   InterPro; IPR015823; Me_CoM_Rdtase_asu_N_sub2.
DR   InterPro; IPR009024; Me_CoM_Rdtase_Fd-like_fold.
DR   NCBIfam; TIGR03256; met_CoM_red_alp; 1.
DR   Pfam; PF02249; MCR_alpha; 1.
DR   Pfam; PF02745; MCR_alpha_N; 1.
DR   PIRSF; PIRSF000262; MCR_alpha; 1.
DR   SUPFAM; SSF48081; Methyl-coenzyme M reductase alpha and beta chain C-terminal domain; 1.
DR   SUPFAM; SSF55088; Methyl-coenzyme M reductase subunits; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Metal-binding; Methanogenesis; Methylation;
KW   Nickel; Reference proteome; Transferase.
FT   CHAIN           1..553
FT                   /note="Methyl-coenzyme M reductase II subunit alpha"
FT                   /id="PRO_0000147457"
FT   BINDING         150
FT                   /ligand="coenzyme F430"
FT                   /ligand_id="ChEBI:CHEBI:60540"
FT                   /ligand_part="Ni"
FT                   /ligand_part_id="ChEBI:CHEBI:28112"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   BINDING         228
FT                   /ligand="coenzyme B"
FT                   /ligand_id="ChEBI:CHEBI:58596"
FT                   /ligand_note="ligand shared between two alpha subunits"
FT                   /note="in chain A"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   BINDING         259..260
FT                   /ligand="coenzyme B"
FT                   /ligand_id="ChEBI:CHEBI:58596"
FT                   /ligand_note="ligand shared between two alpha subunits"
FT                   /note="in chain A"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   BINDING         273
FT                   /ligand="coenzyme B"
FT                   /ligand_id="ChEBI:CHEBI:58596"
FT                   /ligand_note="ligand shared between two alpha subunits"
FT                   /note="in chain B"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   BINDING         335
FT                   /ligand="coenzyme M"
FT                   /ligand_id="ChEBI:CHEBI:58319"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   BINDING         446
FT                   /ligand="coenzyme M"
FT                   /ligand_id="ChEBI:CHEBI:58319"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   MOD_RES         260
FT                   /note="Pros-methylhistidine"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   MOD_RES         274
FT                   /note="5-methylarginine"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   MOD_RES         402
FT                   /note="2-methylglutamine"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   MOD_RES         447
FT                   /note="1-thioglycine"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   MOD_RES         452
FT                   /note="(Z)-2,3-didehydroaspartate"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   MOD_RES         454
FT                   /note="S-methylcysteine"
FT                   /evidence="ECO:0000250|UniProtKB:P58815"
FT   CONFLICT        6
FT                   /note="L -> H (in Ref. 1; AAA73439)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        24
FT                   /note="Y -> I (in Ref. 1; AAA73439)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        168
FT                   /note="I -> V (in Ref. 1; AAA73439)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        200
FT                   /note="K -> KEQLK (in Ref. 1)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   553 AA;  60707 MW;  8A3511715F7EFE00 CRC64;
     MDEKKLFLTA LKKKFEVEDP DEKYTNFYCF GGWEQSARKK EFTEYAKKAA EKRGGIPFYN
     PDIGVPLGQR KLMAYRVSGT DAYVEGDDLH FVNNAAIQQM VDDIKRTVIV GMDTAHAVLE
     KRLGVEVTPE TINEYMEAIN HALPGGAVVQ EHMVEVHPGL VEDCYAKIFT GDDNLADELD
     KRILIDINKE FPEEQAEQLK SYIGNRTYQV NRVPTIVVRT CDGGTVSRWS AMQIGMSFIS
     AYKLCAGEAA IADFSYAAKH ADVIEMGTIM PARRARGPNE PGGVAFGTFA DIVQASRVSD
     DPAKISLEVI AGAAALYDQV WLGSYMSGGV GFTQYATAAY TDDILDDFVY YGMEYVDDKY
     GICGTKPTMD VVRDISTEVT LYSLEQYEEY PTLLEDHFGG SQRAAVAAAA AGCSTAFATG
     NSNAGINGWY LSQILHKEAH SRLGFYGYDL QDQCGASNSL SIRSDEGLIH ELRGPNYPNY
     AMNVGHQPEY AGIAQAPHAA RGDAFCTNPL IKVAFADKDL SFDFTSPRKS IAAGALREFM
     PEGERDLIIP AGK
//