ID   HMT2_MAIZE              Reviewed;         339 AA.
AC   Q9FUM9;
DT   19-JUL-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2001, sequence version 1.
DT   03-AUG-2022, entry version 98.
DE   RecName: Full=Homocysteine S-methyltransferase 2;
DE            EC=2.1.1.10;
DE   AltName: Full=S-methylmethionine:homocysteine methyltransferase 2;
DE            Short=SMM:Hcy S-methyltransferase 2;
DE   AltName: Full=ZmHMT-2;
GN   Name=HMT-2;
OS   Zea mays (Maize).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; PACMAD clade;
OC   Panicoideae; Andropogonodae; Andropogoneae; Tripsacinae; Zea.
OX   NCBI_TaxID=4577;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=11309147; DOI=10.1046/j.1365-313x.2001.00988.x;
RA   Ranocha P., McNeil S.D., Ziemak M.J., Li C., Tarczynski M.C., Hanson A.D.;
RT   "The S-methylmethionine cycle in angiosperms: ubiquity, antiquity and
RT   activity.";
RL   Plant J. 25:575-584(2001).
CC   -!- FUNCTION: Catalyzes methyl transfer from S-methylmethionine (SMM) to
CC       adenosyl-L-homocysteine (AdoMet). SMM degradation (by HMT-1, HMT-2,
CC       HMT-3 and HMT-4) and biosynthesis (by MMT1) constitute the SMM cycle in
CC       plants, which is probably required to achieve short term control of
CC       AdoMet level (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=L-homocysteine + S-methyl-L-methionine = H(+) + 2 L-
CC         methionine; Xref=Rhea:RHEA:26337, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:57844, ChEBI:CHEBI:58199, ChEBI:CHEBI:58252; EC=2.1.1.10;
CC   -!- COFACTOR:
CC       Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC         Evidence={ECO:0000255|PROSITE-ProRule:PRU00333};
CC   -!- SUBUNIT: Monomer. {ECO:0000250}.
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DR   EMBL; AF297045; AAG22538.1; -; mRNA.
DR   RefSeq; NP_001105012.1; NM_001111542.2.
DR   AlphaFoldDB; Q9FUM9; -.
DR   SMR; Q9FUM9; -.
DR   STRING; 4577.GRMZM2G117240_P01; -.
DR   PaxDb; Q9FUM9; -.
DR   EnsemblPlants; Zm00001eb031360_T001; Zm00001eb031360_P001; Zm00001eb031360.
DR   GeneID; 541874; -.
DR   Gramene; Zm00001eb031360_T001; Zm00001eb031360_P001; Zm00001eb031360.
DR   KEGG; zma:541874; -.
DR   eggNOG; KOG1579; Eukaryota.
DR   HOGENOM; CLU_004914_3_2_1; -.
DR   OMA; AQEDYKM; -.
DR   OrthoDB; 731388at2759; -.
DR   Proteomes; UP000007305; Chromosome 1.
DR   ExpressionAtlas; Q9FUM9; baseline and differential.
DR   Genevisible; Q9FUM9; ZM.
DR   GO; GO:0047150; F:betaine-homocysteine S-methyltransferase activity; IEA:InterPro.
DR   GO; GO:0061627; F:S-methylmethionine-homocysteine S-methyltransferase activity; IEA:RHEA.
DR   GO; GO:0008270; F:zinc ion binding; IEA:InterPro.
DR   GO; GO:0009086; P:methionine biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR   Gene3D; 3.20.20.330; -; 1.
DR   InterPro; IPR017226; Betaine-hCys_S-MeTrfase_BHMT.
DR   InterPro; IPR003726; HCY_dom.
DR   InterPro; IPR036589; HCY_dom_sf.
DR   Pfam; PF02574; S-methyl_trans; 1.
DR   PIRSF; PIRSF037505; Betaine_HMT; 1.
DR   SUPFAM; SSF82282; SSF82282; 1.
DR   PROSITE; PS50970; HCY; 1.
PE   2: Evidence at transcript level;
KW   Amino-acid biosynthesis; Metal-binding; Methionine biosynthesis;
KW   Methyltransferase; Reference proteome; S-adenosyl-L-methionine;
KW   Transferase; Zinc.
FT   CHAIN           1..339
FT                   /note="Homocysteine S-methyltransferase 2"
FT                   /id="PRO_0000114615"
FT   DOMAIN          12..326
FT                   /note="Hcy-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT   BINDING         244
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT   BINDING         311
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT   BINDING         312
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
SQ   SEQUENCE   339 AA;  36959 MW;  12B2144B5501F51D CRC64;
     MVVTAAGSAE EAVRRWVDAA GGRLVLDGGL ATELEANGAD LNDPLWSAKC LLSSPHLIRK
     VHMDYLEAGA NIIITASYQA TIQGFESKGF SKEQSENLLT KSVEIALEAR EMFLKEHLEK
     STPIQHPVLV AASLGSYGAY LADGSEYSGD YGEAGTKEFL KDFHRRRLQV LAEAGPDLIA
     FETIPNKLEA EAYVELLEEC NINIPAWFSF NSKDGVHIVS GDSLIECTTI ADKCAKVGAV
     GINCTPPRFI HGLILSIRKV TDKPILIYPN SGERYDGEKK EWVESTGVSD GDFVSYVNEW
     CKDGAVLIGG CCRTTPNTIR AIHRTLNKSP NKQQLPAVE