ID   HNMTB_XENLA             Reviewed;         293 AA.
AC   Q7SYS9;
DT   09-JAN-2007, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2003, sequence version 1.
DT   03-AUG-2022, entry version 65.
DE   RecName: Full=Histamine N-methyltransferase B;
DE            Short=HMT B;
DE            EC=2.1.1.8 {ECO:0000250|UniProtKB:P50135};
GN   Name=hnmt-b;
OS   Xenopus laevis (African clawed frog).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC   Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
OX   NCBI_TaxID=8355;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RG   NIH - Xenopus Gene Collection (XGC) project;
RL   Submitted (JUN-2003) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Inactivates histamine by N-methylation. Plays an important
CC       role in degrading histamine and in regulating the airway response to
CC       histamine. {ECO:0000250|UniProtKB:P50135}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=histamine + S-adenosyl-L-methionine = H(+) + N(tau)-
CC         methylhistamine + S-adenosyl-L-homocysteine; Xref=Rhea:RHEA:19301,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:57856, ChEBI:CHEBI:58432,
CC         ChEBI:CHEBI:58600, ChEBI:CHEBI:59789; EC=2.1.1.8;
CC         Evidence={ECO:0000250|UniProtKB:P50135, ECO:0000255|PROSITE-
CC         ProRule:PRU00929};
CC   -!- SUBUNIT: Monomer. {ECO:0000250|UniProtKB:P50135}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P50135}.
CC   -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC       superfamily. HNMT family. {ECO:0000255|PROSITE-ProRule:PRU00929}.
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; BC054281; AAH54281.1; -; mRNA.
DR   RefSeq; NP_001080614.1; NM_001087145.1.
DR   AlphaFoldDB; Q7SYS9; -.
DR   SMR; Q7SYS9; -.
DR   DNASU; 380306; -.
DR   GeneID; 380306; -.
DR   KEGG; xla:380306; -.
DR   CTD; 380306; -.
DR   Xenbase; XB-GENE-6253788; hnmt.S.
DR   OrthoDB; 870728at2759; -.
DR   Proteomes; UP000186698; Chromosome 9_10S.
DR   Bgee; 380306; Expressed in intestine and 5 other tissues.
DR   GO; GO:0005737; C:cytoplasm; ISS:UniProtKB.
DR   GO; GO:0046539; F:histamine N-methyltransferase activity; ISS:UniProtKB.
DR   GO; GO:0001695; P:histamine catabolic process; ISS:UniProtKB.
DR   GO; GO:0032259; P:methylation; ISS:UniProtKB.
DR   Gene3D; 3.40.50.150; -; 1.
DR   InterPro; IPR016673; HHMT-like.
DR   InterPro; IPR029063; SAM-dependent_MTases_sf.
DR   PIRSF; PIRSF016616; HHMT; 1.
DR   SUPFAM; SSF53335; SSF53335; 1.
DR   PROSITE; PS51597; SAM_HNMT; 1.
PE   2: Evidence at transcript level;
KW   Cytoplasm; Methyltransferase; Reference proteome; S-adenosyl-L-methionine;
KW   Transferase.
FT   CHAIN           1..293
FT                   /note="Histamine N-methyltransferase B"
FT                   /id="PRO_0000271427"
FT   BINDING         28
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00929"
FT   BINDING         60
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00929"
FT   BINDING         89
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00929"
FT   BINDING         94
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00929"
FT   BINDING         120
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00929"
FT   BINDING         142
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00929"
FT   BINDING         283
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00929"
SQ   SEQUENCE   293 AA;  33060 MW;  A9ACB64AA1F48BB3 CRC64;
     MDSGLRSLLS DHSRYVESFR LFLQNSTEHQ CMQHFIETKL PDIISSIGND KPVIDVLGIG
     SGSGEIDLQM IAKIQARWPG VSINNQIVEP SAEQILGYKE RVAKAPNLGY VTFSWHHQTS
     SEFEHRVTED KQMTKYDFIH MIQMLYYVKD VPGTLKFFKS CLAPNGKLLI ILVSGNSGWA
     PLWKKYGQRL PLNDLCLYVT AGDIAEMLSS MGARFQSHEL QSDMDITKCF IEGDKNGELL
     LDFLTETCDF RKNAPAELRD QIICDLKSPR CSTTKDGKVI FNNNLSVIVV EAD