ID   HMT3_ARATH              Reviewed;         347 AA.
AC   Q8LAX0; Q9LUI7;
DT   19-JUL-2004, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2004, sequence version 2.
DT   16-JUN-2009, entry version 41.
DE   RecName: Full=Homocysteine S-methyltransferase 3;
DE            EC=2.1.1.10;
DE   AltName: Full=S-methylmethionine:homocysteine methyltransferase 3;
DE            Short=SMM:Hcy S-methyltransferase 3;
DE            Short=AtHMT-3;
GN   Name=HMT3; OrderedLocusNames=At3g22740; ORFNames=MWI23.11;
OS   Arabidopsis thaliana (Mouse-ear cress).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliophyta; eudicotyledons; core eudicotyledons;
OC   rosids; eurosids II; Brassicales; Brassicaceae; Arabidopsis.
OX   NCBI_TaxID=3702;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], ENZYME ACTIVITY, PROBABLE FUNCTION OF SMM
RP   CYCLE, BIOPHYSICOCHEMICAL PROPERTIES, AND TISSUE SPECIFICITY.
RC   STRAIN=cv. Columbia; TISSUE=Leaf;
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.,
RA   Hanson A.D.;
RT   "The S-methylmethionine cycle in angiosperms: ubiquity, antiquity and
RT   activity.";
RL   Plant J. 25:575-584(2001).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   MEDLINE=20277480; 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   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=cv. Columbia;
RX   MEDLINE=21932900; PubMed=11910074; DOI=10.1126/science.1071006;
RA   Seki M., Narusaka M., Kamiya A., Ishida J., Satou M., Sakurai T.,
RA   Nakajima M., Enju A., Akiyama K., Oono Y., Muramatsu M.,
RA   Hayashizaki Y., Kawai J., Carninci P., Itoh M., Ishii Y., Arakawa T.,
RA   Shibata K., Shinagawa A., Shinozaki K.;
RT   "Functional annotation of a full-length Arabidopsis cDNA collection.";
RL   Science 296:141-145(2002).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=cv. Columbia;
RX   MEDLINE=22954850; PubMed=14593172; DOI=10.1126/science.1088305;
RA   Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J.,
RA   Southwick A.M., Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F.,
RA   Karlin-Newmann G., Liu S.X., Lam B., Sakano H., Wu T., Yu G.,
RA   Miranda M., Quach H.L., Tripp M., Chang C.H., Lee J.M., Toriumi M.J.,
RA   Chan M.M., Tang C.C., Onodera C.S., Deng J.M., Akiyama K., Ansari Y.,
RA   Arakawa T., Banh J., Banno F., Bowser L., Brooks S.Y., Carninci P.,
RA   Chao Q., Choy N., Enju A., Goldsmith A.D., Gurjal M., Hansen N.F.,
RA   Hayashizaki Y., Johnson-Hopson C., Hsuan V.W., Iida K., Karnes M.,
RA   Khan S., Koesema E., Ishida J., Jiang P.X., Jones T., Kawai J.,
RA   Kamiya A., Meyers C., Nakajima M., Narusaka M., Seki M., Sakurai T.,
RA   Satou M., Tamse R., Vaysberg M., Wallender E.K., Wong C., Yamamura Y.,
RA   Yuan S., Shinozaki K., Davis R.W., Theologis A., Ecker J.R.;
RT   "Empirical analysis of transcriptional activity in the Arabidopsis
RT   genome.";
RL   Science 302:842-846(2003).
RN   [5]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RA   Brover V.V., Troukhan M.E., Alexandrov N.A., Lu Y.-P., Flavell R.B.,
RA   Feldmann K.A.;
RT   "Full-length cDNA from Arabidopsis thaliana.";
RL   Submitted (MAR-2002) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Catalyzes methyl transfer from S-methylmethionine (SMM)
CC       to adenosyl-L-homocysteine (AdoMet). SMM degradation (by HMT-1,
CC       HMT-2 and HMT-3) and biosynthesis (by MMT1) constitute the SMM
CC       cycle in plants, which is probably required to achieve short term
CC       control of AdoMet level.
CC   -!- CATALYTIC ACTIVITY: S-adenosyl-L-methionine + L-homocysteine = S-
CC       adenosyl-L-homocysteine + L-methionine.
CC   -!- COFACTOR: Zinc (Potential).
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=335 uM for S-methylmethionine;
CC         KM=1760 uM for (S,S)-AdoMet;
CC   -!- SUBUNIT: Monomer (By similarity).
CC   -!- TISSUE SPECIFICITY: Expressed predominantly in rosette leaves.
CC       Expressed in roots, cauline leaves and developing seeds.
CC   -!- MISCELLANEOUS: In contrast to HMT-1, it is not inhibited by
CC       methionine.
CC   -!- SIMILARITY: Contains 1 Hcy-binding domain.
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DR   EMBL; AF297394; AAG10301.1; -; mRNA.
DR   EMBL; AB022223; BAB01249.1; -; Genomic_DNA.
DR   EMBL; AK118021; BAC42654.1; -; mRNA.
DR   EMBL; BT005318; AAO63382.1; -; mRNA.
DR   EMBL; AY087554; AAM65096.1; -; mRNA.
DR   IPI; IPI00516296; -.
DR   RefSeq; NP_566715.1; -.
DR   UniGene; At.6305; -.
DR   PRIDE; Q8LAX0; -.
DR   GeneID; 821845; -.
DR   GenomeReviews; BA000014_GR; AT3G22740.
DR   KEGG; ath:AT3G22740; -.
DR   NMPDR; fig|3702.1.peg.14522; -.
DR   TAIR; At3g22740; -.
DR   OMA; Q8LAX0; AWFSFTS.
DR   BRENDA; 2.1.1.10; 302.
DR   ArrayExpress; Q8LAX0; -.
DR   GermOnline; AT3G22740; Arabidopsis thaliana.
DR   GO; GO:0005886; C:plasma membrane; IDA:TAIR.
DR   GO; GO:0008898; F:homocysteine S-methyltransferase activity; IEA:EC.
DR   GO; GO:0008270; F:zinc ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0009086; P:methionine biosynthetic process; IEA:UniProtKB-KW.
DR   InterPro; IPR003726; S_MeTrfase.
DR   Gene3D; G3DSA:3.20.20.330; S_methyl_trans; 1.
DR   Pfam; PF02574; S-methyl_trans; 1.
DR   PROSITE; PS50970; HCY; 1.
PE   1: Evidence at protein level;
KW   Amino-acid biosynthesis; Complete proteome; Metal-binding;
KW   Methionine biosynthesis; Methyltransferase; S-adenosyl-L-methionine;
KW   Transferase; Zinc.
FT   CHAIN         1    347       Homocysteine S-methyltransferase 3.
FT                                /FTId=PRO_0000114613.
FT   DOMAIN       12    333       Hcy-binding.
FT   METAL       251    251       Zinc (Potential).
FT   METAL       318    318       Zinc (Potential).
FT   METAL       319    319       Zinc (Potential).
FT   CONFLICT     24     24       A -> E (in Ref. 5; AAM65096).
FT   CONFLICT     45     45       L -> I (in Ref. 5; AAM65096).
FT   CONFLICT    117    117       C -> W (in Ref. 5; AAM65096).
SQ   SEQUENCE   347 AA;  37882 MW;  45CDC34973F820CC CRC64;
     MGSFVKEETS SLMTDFLEKC GGYAVVDGGF ATELQRHGAD INDPLWSAKC LITSPHLVTK
     VHLDYLESGA NIIITASYQA TIQGFVAKGL SVGEAENLLR RSVEITYEAR EIFYNRCTKG
     SWDFAYAGKA SRRPILVAAS VGSYGAYLAD GSEYSGIYGD SVSKETLKDF HRRRVQILAK
     SGADLIAFET IPNKLEAEAY ADLLEEEDID IPAWFSFTSK DGVSVPRGDS VVECAKVADS
     CKNVVAIGIN CTAPRYIHAL IISLRQMTRK PIVVYPNSGE VYDGLNKKWI KSEGESEEDF
     VSYVSKWRDA GASLFGGCCR TTPNTIRAIA KVLSDEPSAA SKPKFGQ
//