ID   MTRB_METKA              Reviewed;         112 AA.
AC   O32866;
DT   15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   25-MAY-2022, entry version 108.
DE   RecName: Full=Tetrahydromethanopterin S-methyltransferase subunit B;
DE            EC=2.1.1.86;
DE   AltName: Full=N5-methyltetrahydromethanopterin--coenzyme M methyltransferase subunit B;
GN   Name=mtrB; OrderedLocusNames=MK0659;
OS   Methanopyrus kandleri (strain AV19 / DSM 6324 / JCM 9639 / NBRC 100938).
OC   Archaea; Euryarchaeota; Methanopyri; Methanopyrales; Methanopyraceae;
OC   Methanopyrus.
OX   NCBI_TaxID=190192;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=9461302; DOI=10.1111/j.1432-1033.1997.00783.x;
RA   Harms U., Thauer R.K.;
RT   "Identification of the active site histidine in the corrinoid protein MtrA
RT   of the energy-conserving methyltransferase complex from Methanobacterium
RT   thermoautotrophicum.";
RL   Eur. J. Biochem. 250:783-788(1997).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=AV19 / DSM 6324 / JCM 9639 / NBRC 100938;
RX   PubMed=11930014; DOI=10.1073/pnas.032671499;
RA   Slesarev A.I., Mezhevaya K.V., Makarova K.S., Polushin N.N.,
RA   Shcherbinina O.V., Shakhova V.V., Belova G.I., Aravind L., Natale D.A.,
RA   Rogozin I.B., Tatusov R.L., Wolf Y.I., Stetter K.O., Malykh A.G.,
RA   Koonin E.V., Kozyavkin S.A.;
RT   "The complete genome of hyperthermophile Methanopyrus kandleri AV19 and
RT   monophyly of archaeal methanogens.";
RL   Proc. Natl. Acad. Sci. U.S.A. 99:4644-4649(2002).
CC   -!- FUNCTION: Part of a complex that catalyzes the formation of methyl-
CC       coenzyme M and tetrahydromethanopterin from coenzyme M and methyl-
CC       tetrahydromethanopterin. This is an energy-conserving, sodium-ion
CC       translocating step. {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=5-methyl-5,6,7,8-tetrahydromethanopterin + coenzyme M + 2
CC         Na(+)(in) = 5,6,7,8-tetrahydromethanopterin + methyl-coenzyme M + 2
CC         Na(+)(out); Xref=Rhea:RHEA:53492, ChEBI:CHEBI:29101,
CC         ChEBI:CHEBI:58103, ChEBI:CHEBI:58116, ChEBI:CHEBI:58286,
CC         ChEBI:CHEBI:58319; EC=2.1.1.86;
CC   -!- PATHWAY: One-carbon metabolism; methanogenesis from CO(2); methyl-
CC       coenzyme M from 5,10-methylene-5,6,7,8-tetrahydromethanopterin: step
CC       2/2.
CC   -!- SUBUNIT: The complex is composed of 8 subunits; MtrA, MtrB, MtrC, MtrD,
CC       MtrE, MtrF, MtrG and MtrH. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000305}; Single-pass membrane
CC       protein {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the MtrB family. {ECO:0000305}.
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DR   EMBL; Y14428; CAA74770.1; -; Genomic_DNA.
DR   EMBL; AE009439; AAM01874.1; -; Genomic_DNA.
DR   AlphaFoldDB; O32866; -.
DR   SMR; O32866; -.
DR   STRING; 190192.MK0659; -.
DR   EnsemblBacteria; AAM01874; AAM01874; MK0659.
DR   KEGG; mka:MK0659; -.
DR   HOGENOM; CLU_171544_0_0_2; -.
DR   OMA; TNMVYGF; -.
DR   UniPathway; UPA00640; UER00698.
DR   Proteomes; UP000001826; Chromosome.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0030269; F:tetrahydromethanopterin S-methyltransferase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0019386; P:methanogenesis, from carbon dioxide; IEA:UniProtKB-UniPathway.
DR   GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR   GO; GO:0006730; P:one-carbon metabolic process; IEA:UniProtKB-UniRule.
DR   HAMAP; MF_01094; MtrB; 1.
DR   InterPro; IPR008690; MtrB_MeTrfase.
DR   Pfam; PF05440; MtrB; 1.
DR   PIRSF; PIRSF005518; MtrB; 1.
DR   TIGRFAMs; TIGR04166; methano_MtrB; 1.
PE   3: Inferred from homology;
KW   Cell membrane; Membrane; Methanogenesis; Methyltransferase;
KW   One-carbon metabolism; Reference proteome; Transferase; Transmembrane;
KW   Transmembrane helix.
FT   CHAIN           1..112
FT                   /note="Tetrahydromethanopterin S-methyltransferase subunit
FT                   B"
FT                   /id="PRO_0000147515"
FT   TRANSMEM        80..100
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   112 AA;  12227 MW;  FE83EF77EB8583BA CRC64;
     MAIVLIDPES QIAMDAVTGA VAEWSEDVVT LDVMPLYEKV EELEQYVNDM MRAMDPSTTT
     WGTLPGREGV HETAGFLTNF AHGFVIGTMI VALVAFTLAA VYKLHALRLL GL