Meth_synt_2

• PFAM accession number: PF01717
• Interpro abstract (IPR002629):

  The N-terminal half and C-terminal half of MetE in E. coli show some sequence similarity, indicating that the metE gene has evolved from an ancestral metE gene by duplication [ (PUBMED:1339288) ]. This entry represents a the C-terminal domain of cobalamin-independent methionine synthase (MetE) from bacteria and plants. It also includes archaeal proteins where this domain corresponds to the entire length of the protein [ (PUBMED:10469143) ].

  Methionine synthases catalyse the the final step of methionine biosynthesis. Two apparently unrelated families of proteins catalyse this step: cobalamin-dependent methionine synthase, which catalyses the transfer of a methyl group from N5-methyltetrahydrofolate to L-homocysteine and requires cobalamin as a cofactor (MetH; 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase; EC 2.1.1.13 ) and cobalamin-independent methionine synthase, which catalyses the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine without using an intermediate methyl carrier (MetE; 5-methyltetrahydropteroyltri-L-glutamate:L-homocysteine S-methyltransferase; EC 2.1.1.14 ). These enzymes display no detectable sequence homology between them, but both require zinc for activation and binding to L-homocysteine. Organisms that cannot obtain cobalamin (vitamin B12) encode only the cobalamin-independent enzyme. Escherichia coli and many other bacteria express both enzymes [ (PUBMED:1339288) ]. Mammals utilise only cobalamin-dependent methionine synthase, while plants and yeasts utilise only the cobalamin-independent enzyme.

• GO process: methionine biosynthetic process (GO:0009086)
• GO function: zinc ion binding (GO:0008270), 5-methyltetrahydropteroyltriglutamate-homocysteine S-methyltransferase activity (GO:0003871)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry Meth_synt_2