Reviewed, UniProtKB/Swiss-Prot Q9MBC2 (MMT1_HORVU)

Names and origin

Protein names

Recommended name:
    Methionine S-methyltransferase
    EC=2.1.1.12
Alternative name(s):
    AdoMet:Met S-methyltransferase
    Hv-MMT1

Gene names

Name:	MMT1
Synonyms:	MMT

Organism

Hordeum vulgare (Barley)

Taxonomic identifier

4513 [NCBI]

Taxonomic lineage

Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › Liliopsida › Poales › Poaceae › BEP clade › Pooideae › Triticeae › Hordeum

Protein attributes

Sequence length	1088 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Catalyzes the S-methylmethionine (SMM) biosynthesis from adenosyl-L-homocysteine (AdoMet) and methionine. SMM biosynthesis (by MMT1) and degradation (by HMT-1, HMT-2 and HMT-3) constitute the SMM cycle in plants, which is probably required to achieve short term control of AdoMet level. Also able to catalyze the selenium-methylmethionine (SeMM) from AdoMet and selenium-methionine (SeMet). May play a role in phoem sulfur transport; such function is however not essential.
Catalytic activity	S-adenosyl-L-methionine + L-methionine = S-adenosyl-L-homocysteine + S-methyl-L-methionine. Ref.2
Subunit structure	Homotetramer By similarity.
Subcellular location	Cytoplasm By similarity.
Tissue specificity	Expressed in the shoot, scutellum, and aleurone cells but not in the root or endosperm. Ref.2
Developmental stage	Increases during germination.
Sequence similarities	Belongs to the methyltransferase superfamily.

Ontologies

Keywords
Cellular component	Cytoplasm
Ligand	S-adenosyl-L-methionine
Molecular function	Methyltransferase Transferase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Cellular component	cytoplasm Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	methionine S-methyltransferase activity Inferred from electronic annotation. Source: EC pyridoxal phosphate binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 1088	1088	Methionine S-methyltransferase		PRO_0000204461

Sequences

	Sequence		Length	Mass (Da)
	Q9MBC2-1 [UniParc]. Last modified October 1, 2000. Version 1. Checksum: F1CB112F456C050B	FASTA	1,088	119,881
	10 20 30 40 50 60 MAAAAGDVEA FLAACQASGD AAYGAAKAVL ERLEAPATRA EARRLLGAVR RRFAAGGPAA 70 80 90 100 110 120 GLECFRTFHF RIHDVVLDPH LQGFQQRKKL TMMEIPSIFI PEDWSFTFYE GLNRHPDSIF 130 140 150 160 170 180 RDKTVAELGC GNGWISIALA EKWCPSKVYG LDINPRPIKI AWINLYLNAL DDDGLPIYDA 190 200 210 220 230 240 EGKTLLDRVE FYESDLLSYC RDNKIELDRI VGCIPQILNP NPEAMSKIVT ENSSEEFLYS 250 260 270 280 290 300 LSNYCALQGF VEDQFGLGLI ARAVEEGISV IKPSGLMVFN MGGRPGQGVC ERLFLRRGFR 310 320 330 340 350 360 INKLWQTKIM QAADTDISAL VEIEKNSRHR FEFFMDLVGD QPVCARTAWA YMKSGGRISH 370 380 390 400 410 420 ALSVYSCQLR QPNQVKKIFE FLKDGFHEVS SSLDLSFDDD SVADEKIPFL AYLASFLQEN 430 440 450 460 470 480 KSNPCEPPAG CLNFRNLVAG FMKSYHHIPL TPDNVVVFPS RAVAIENALR LFSPGLAIVD 490 500 510 520 530 540 EHLTRHLPKQ WLTSLAIEES NHAKDTVTVI EAPRQSDLLI ELIRKLKPQV VVTGMAQFEA 550 560 570 580 590 600 ITSAAFVNLL SVTKDVGSRL LLDISEHLEL SSLPSSNGVL KYLAGKTLPS HAAILCGLVK 610 620 630 640 650 660 NQVYSDLEVA FAISEDPTVY KALSQTIELL EGHTSVISQH YYGCLFHELL AFQIGDRHPQ 670 680 690 700 710 720 QEREPAEVIS KEMIGFSSSA MSTLEGAEFF VPGSMESGVI HMDLDRSFLP VPSAVNASIF 730 740 750 760 770 780 ESFVRQNITD SETDVRSSIQ QLVKDSYGFS AGGASEIIYG NTCLALFNKL VLCCMQEQGT 790 800 810 820 830 840 LLFPLGTNGH YVNAAKFVNA TTLTIPTKAD SGFKIEPSAL ADTLEKVSQP WVYISGPTIN 850 860 870 880 890 900 PTGFLYSDDD IAELLSVCAT YGARVVIDTS SSGLEFQATG CSQWNLERCL SNVKSSKPSF 910 920 930 940 950 960 SVVLLGELSF ELTTAGLDFG FLIMSDSSLV DTFYSFPSLS RPHSTLKYTF RKLLGLKNQK 970 980 990 1000 1010 1020 DQHFSDLILE QKETLKNRAD QLIKMLESCG WDAVGCHGGI SMLAKPTAYI GKSLKVDGFE 1030 1040 1050 1060 1070 1080 GKLDSHNMRE ALLRSTGLCI SSSGWTGVPD YCRFSFALES GDFDRAMECI ARFRELVLGG GAKVNGSN

References

[1]	"Cloning and expression studies of S-adenosyl-L-methionine:L-methionine S-methyltransferase (MMT) in germinating barley." Pimenta M., Kaneta T., Kamiya Y. Submitted (JUN-1999) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: cv. Haruna Nijo.
[2]	"S-adenosyl-L-methionine:L-methionine S-methyltransferase from germinating barley. Purification and localization." Pimenta M.J., Kaneta T., Larondelle Y., Dohmae N., Kamiya Y. Plant Physiol. 118:431-438(1998) [PubMed: 9765528] [Abstract] Cited for: PROTEIN SEQUENCE OF 159-183, ENZYME ACTIVITY, TISSUE SPECIFICITY.

Cross-references

Sequence databases
EMBLGenBankDDBJ	AB028870 mRNA. Translation: BAA94795.1.
3D structure databases
ModBase	Search...
Organism-specific databases
Gramene	Q9MBC2.
Enzyme and pathway databases
BRENDA	2.1.1.12. 283.
Family and domain databases
InterPro	IPR015421. PyrdxlP-dep_Trfase_major_sub1. IPR015422. PyrdxlP-dep_Trfase_major_sub2. IPR007848. Small_mtfrase. [Graphical view]
Gene3D	G3DSA:3.40.640.10. PyrdxlP-dep_Trfase_major_sub1. 1 hit. G3DSA:3.90.1150.10. PyrdxlP-dep_Trfase_major_sub2. 1 hit.
Pfam	PF05175. MTS. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

MMT1_HORVU

Accession

Primary (citable) accession number: Q9MBC2

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 19, 2004
Last sequence update:	October 1, 2000
Last modified:	June 16, 2009
This is version 40 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)