S-adenosylmethionine [SAM] synthetase-alpha/beta (S-adenosylmethionine synthetase isoform type-1, AdoMet synthetase 1, MAT1A, AMS1, MATA1, MAT-I/III)

Function

• catalyzes the formation of S-adenosylmethionine from methionine & ATP
• amino-acid biosynthesis; S-adenosyl-L-methionine biosynthesis
• S-adenosyl-L-methionine from L-methionine: step 1/1 context: activated methyl cycle

ATP + L-methionine + H2O
          <-->
phosphate + diphosphate + S-adenosyl-L-methionine

Cofactor:

• binds 2 divalent ions per subunit, Mg+2 or cobalt
• binds 1 K+ per subunit (putative)

Structure

• homotetramer (MAT-I) or homodimer (MAT-III)
• belongs to the AdoMet synthetase family

Expression

expressed in liver

Pathology

• defects in MAT1A are a cause of a form of hypermethioninemia

More general terms

• methionine adenosyl transferase

Database

• UniProt: http://www.uniprot.org/uniprot/Q00266.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4143
• OMIM: https://mirror.omim.org/entry/250850