IUBMB Enzyme Nomenclature


Accepted name: selenocysteine Se-methyltransferase

Reaction: S-methyl-L-methionine + L-selenocysteine = L-methionine + Se-methyl-L-selenocysteine

Other name(s): SMT

Systematic name: S-methyl-L-methionine:L-selenocysteine Se-methyltransferase

Comments: The enzyme uses S-adenosyl-L-methionine as methyl donor less actively than S-methyl-L-methionine. The enzyme from broccoli (Brassica oleracea var. italica) also has the activity of EC, homocysteine S-methyltransferase [4].

Links to other databases: BRENDA, EXPASY, KEGG Metacyc, CAS registry number:


1. Neuhierl, B. and Bock, A. On the mechanism of selenium tolerance in selenium-accumulating plants. Purification and characterization of a specific selenocysteine methyltransferase from cultured cells of Astragalus bisculatus. Eur. J. Biochem. 239 (1996) 235-238. [PMID: 8706715]

2. Neuhierl, B., Thanbichler, M., Lottspeich, F. and Bock, A. A family of S-methylmethionine-dependent thiol/selenol methyltransferases. Role in selenium tolerance and evolutionary relation. J. Biol. Chem. 274 (1999) 5407-5414. [PMID: 10026151]

3. Lyi, S.M., Heller, L.I., Rutzke, M., Welch, R.M., Kochian, L.V. and Li, L. Molecular and biochemical characterization of the selenocysteine Se-methyltransferase gene and Se-methylselenocysteine synthesis in broccoli. Plant Physiol. 138 (2005) 409-420. [PMID: 15863700]

4. Lyi, S.M., Zhou, X., Kochian, L.V. and Li, L. Biochemical and molecular characterization of the homocysteine S-methyltransferase from broccoli (Brassica oleracea var. italica). Phytochemistry 68 (2007) 1112-1119. [PMID: 17391716]

[EC created 2013]

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