HMT1_ARATH
ID HMT1_ARATH Reviewed; 326 AA.
AC Q9SDL7;
DT 19-JUL-2004, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-2000, sequence version 1.
DT 03-AUG-2022, entry version 123.
DE RecName: Full=Homocysteine S-methyltransferase 1;
DE EC=2.1.1.10;
DE AltName: Full=S-methylmethionine:homocysteine methyltransferase 1;
DE Short=AtHMT-1;
DE Short=SMM:Hcy S-methyltransferase 1;
GN Name=HMT-1; OrderedLocusNames=At3g25900; ORFNames=MPE11.5, MPE11.6;
OS Arabidopsis thaliana (Mouse-ear cress).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis.
OX NCBI_TaxID=3702;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], ENZYME ACTIVITY, ACTIVITY REGULATION,
RP AND SUBUNIT.
RX PubMed=10747987; DOI=10.1074/jbc.m001116200;
RA Ranocha P., Bourgis F., Ziemak M.J., Rhodes D., Gage D.A., Hanson A.D.;
RT "Characterization and functional expression of cDNAs encoding methionine-
RT sensitive and -insensitive homocysteine S-methyltransferases from
RT Arabidopsis.";
RL J. Biol. Chem. 275:15962-15968(2000).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=cv. Columbia;
RX PubMed=10819329; DOI=10.1093/dnares/7.2.131;
RA Sato S., Nakamura Y., Kaneko T., Katoh T., Asamizu E., Tabata S.;
RT "Structural analysis of Arabidopsis thaliana chromosome 3. I. Sequence
RT features of the regions of 4,504,864 bp covered by sixty P1 and TAC
RT clones.";
RL DNA Res. 7:131-135(2000).
RN [3]
RP GENOME REANNOTATION.
RC STRAIN=cv. Columbia;
RX PubMed=27862469; DOI=10.1111/tpj.13415;
RA Cheng C.Y., Krishnakumar V., Chan A.P., Thibaud-Nissen F., Schobel S.,
RA Town C.D.;
RT "Araport11: a complete reannotation of the Arabidopsis thaliana reference
RT genome.";
RL Plant J. 89:789-804(2017).
RN [4]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC STRAIN=cv. Columbia;
RX PubMed=14593172; DOI=10.1126/science.1088305;
RA Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J., Southwick A.M.,
RA Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F., Karlin-Newmann G.,
RA Liu S.X., Lam B., Sakano H., Wu T., Yu G., Miranda M., Quach H.L.,
RA Tripp M., Chang C.H., Lee J.M., Toriumi M.J., Chan M.M., Tang C.C.,
RA Onodera C.S., Deng J.M., Akiyama K., Ansari Y., Arakawa T., Banh J.,
RA Banno F., Bowser L., Brooks S.Y., Carninci P., Chao Q., Choy N., Enju A.,
RA Goldsmith A.D., Gurjal M., Hansen N.F., Hayashizaki Y., Johnson-Hopson C.,
RA Hsuan V.W., Iida K., Karnes M., Khan S., Koesema E., Ishida J., Jiang P.X.,
RA Jones T., Kawai J., Kamiya A., Meyers C., Nakajima M., Narusaka M.,
RA Seki M., Sakurai T., Satou M., Tamse R., Vaysberg M., Wallender E.K.,
RA Wong C., Yamamura Y., Yuan S., Shinozaki K., Davis R.W., Theologis A.,
RA Ecker J.R.;
RT "Empirical analysis of transcriptional activity in the Arabidopsis
RT genome.";
RL Science 302:842-846(2003).
RN [5]
RP PROBABLE FUNCTION OF SMM CYCLE, BIOPHYSICOCHEMICAL PROPERTIES, AND TISSUE
RP SPECIFICITY.
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 and
CC HMT-3) and biosynthesis (by MMT1) constitute the SMM cycle in plants,
CC which is probably required to achieve short term control of AdoMet
CC level.
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 Evidence={ECO:0000269|PubMed:10747987};
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC Evidence={ECO:0000255|PROSITE-ProRule:PRU00333};
CC -!- ACTIVITY REGULATION: Strongly inhibited by methionine.
CC {ECO:0000269|PubMed:10747987}.
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=29 uM for S-methylmethionine {ECO:0000269|PubMed:11309147};
CC KM=1950 uM for (S,S)-AdoMet {ECO:0000269|PubMed:11309147};
CC -!- SUBUNIT: Monomer. {ECO:0000269|PubMed:10747987}.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=1;
CC Comment=A number of isoforms are produced. According to EST
CC sequences.;
CC Name=1;
CC IsoId=Q9SDL7-1; Sequence=Displayed;
CC -!- TISSUE SPECIFICITY: Expressed predominantly in roots. Expressed in
CC rosette leaves, cauline leaves and developing seeds.
CC {ECO:0000269|PubMed:11309147}.
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DR EMBL; AF219222; AAF23821.1; -; Genomic_DNA.
DR EMBL; AB023041; BAB01052.1; -; Genomic_DNA.
DR EMBL; CP002686; AEE77087.1; -; Genomic_DNA.
DR EMBL; AY065163; AAL38339.1; -; mRNA.
DR EMBL; AY081604; AAM10166.1; -; mRNA.
DR PIR; T51941; T51941.
DR RefSeq; NP_189219.1; NM_113493.5. [Q9SDL7-1]
DR AlphaFoldDB; Q9SDL7; -.
DR SMR; Q9SDL7; -.
DR BioGRID; 7517; 1.
DR IntAct; Q9SDL7; 1.
DR STRING; 3702.AT3G25900.1; -.
DR PaxDb; Q9SDL7; -.
DR PRIDE; Q9SDL7; -.
DR ProteomicsDB; 230262; -. [Q9SDL7-1]
DR EnsemblPlants; AT3G25900.1; AT3G25900.1; AT3G25900. [Q9SDL7-1]
DR GeneID; 822186; -.
DR Gramene; AT3G25900.1; AT3G25900.1; AT3G25900. [Q9SDL7-1]
DR KEGG; ath:AT3G25900; -.
DR Araport; AT3G25900; -.
DR TAIR; locus:2092120; AT3G25900.
DR eggNOG; KOG1579; Eukaryota.
DR OMA; HRPRMKA; -.
DR OrthoDB; 731388at2759; -.
DR PhylomeDB; Q9SDL7; -.
DR BioCyc; ARA:AT3G25900-MON; -.
DR BioCyc; MetaCyc:AT3G25900-MON; -.
DR BRENDA; 2.1.1.10; 399.
DR SABIO-RK; Q9SDL7; -.
DR PRO; PR:Q9SDL7; -.
DR Proteomes; UP000006548; Chromosome 3.
DR ExpressionAtlas; Q9SDL7; baseline and differential.
DR Genevisible; Q9SDL7; AT.
DR GO; GO:0047150; F:betaine-homocysteine S-methyltransferase activity; IEA:InterPro.
DR GO; GO:0008898; F:S-adenosylmethionine-homocysteine S-methyltransferase activity; IDA:TAIR.
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; IDA:TAIR.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR GO; GO:0033528; P:S-methylmethionine cycle; IBA:GO_Central.
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 1: Evidence at protein level;
KW Alternative splicing; Amino-acid biosynthesis; Metal-binding;
KW Methionine biosynthesis; Methyltransferase; Reference proteome;
KW S-adenosyl-L-methionine; Transferase; Zinc.
FT CHAIN 1..326
FT /note="Homocysteine S-methyltransferase 1"
FT /id="PRO_0000114611"
FT DOMAIN 9..323
FT /note="Hcy-binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT BINDING 241
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT BINDING 308
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT BINDING 309
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
SQ SEQUENCE 326 AA; 35980 MW; EBE5F904FDA8DC99 CRC64;
MVLEKKSALL EDLIKKCGGC AVVDGGFATQ LEIHGAAIND PLWSAVSLIK NPELIKRVHM
EYLEAGADIV VTSSYQATIP GFLSRGLSIE ESESLLQKSV ELAVEARDRF WEKVSKVSGH
SYNRALVAAS IGSYGAYLAD GSEYSGHYGE NVSLDKLKDF HRRRLQVLVE AGPDLLAFET
IPNKLEAQAC VELLEEEKVQ IPAWICFTSV DGEKAPSGES FEECLEPLNK SNNIYAVGIN
CAPPQFIENL IRKFAKLTKK AIVVYPNSGE VWDGKAKQWL PSQCFGDDEF EMFATKWRDL
GAKLIGGCCR TTPSTINAIS RDLKRR
