IUBMB Enzyme Nomenclature

EC 2.1.1.98

Accepted name: diphthine synthase

Reaction: 3 S-adenosyl-L-methionine + 2-(3-carboxy-3-aminopropyl)-L-histidine-[translation elongation factor 2] = 3 S-adenosyl-L-homocysteine + 2-[3-carboxy-3-(trimethylammonio)propyl]-L-histidine-[translation elongation factor 2] (overall reaction)
(1a) S-adenosyl-L-methionine + 2-(3-carboxy-3-aminopropyl)-L-histidine-[translation elongation factor 2] = S-adenosyl-L-homocysteine + 2-[3-carboxy-3-(methylammonio)propyl]-L-histidine-[translation elongation factor 2]
(1b) S-adenosyl-L-methionine + 2-[3-carboxy-3-(methylammonio)propyl]-L-histidine-[translation elongation factor 2] = S-adenosyl-L-homocysteine + 2-[3-carboxy-3-(dimethylammonio)propyl]-L-histidine-[translation elongation factor 2]
(1c) S-adenosyl-L-methionine + 2-[3-carboxy-3-(dimethylammonio)propyl]-L-histidine-[translation elongation factor 2] = S-adenosyl-L-homocysteine + 2-[3-carboxy-3-(trimethylammonio)propyl]-L-histidine-[translation elongation factor 2]

For diagram of reaction click here.

Glossary: diphthine = 2-[3-carboxy-3-(trimethylammonio)propyl]-L-histidine

Other name(s): S-adenosyl-L-methionine:elongation factor 2 methyltransferase; diphthine methyltransferase; S-adenosyl-L-methionine:2-(3-carboxy-3-aminopropyl)-L-histidine methyltransferase

Systematic name: S-adenosyl-L-methionine:2-(3-carboxy-3-aminopropyl)-L-histidine-[translation elongation factor 2] methyltransferase

Comments: The trimethylated product, diphthine, is converted into diphthamide by EC 6.3.1.14, diphthine—ammonia ligase. The relevant histidine of EF2 is His715 in mammals, His699 in yeast and His600 in Pyrococcus horikoshii.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 114514-25-9

References:

1. Chen, J.-Y.C. and Bodley, J.W. Biosynthesis of diphthamide in Saccharomyces cerevisiae. Partial purification and characterization of a specific S-adenosylmethionine:elongation factor 2 methyltransferase. J. Biol. Chem. 263 (1988) 11692-11696. [PMID: 3042777]

2. Moehring, J.M. and Moehring, T.J. The post-translational trimethylation of diphthamide studied in vitro. J. Biol. Chem. 263 (1988) 3840-3844. [PMID: 3346227]

[EC 2.1.1.98 created 1990, modified 2013]


Return to EC 2.1.1 home page
Return to EC 2.1 home page
Return to EC 2 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page