Reaction: S-adenosyl-L-methionine + 2-(3-carboxy-3-aminopropyl)-L-histidine = S-adenosyl-L-homocysteine + 2-[3-carboxy-3-(methylammonio)propyl]-L-histidine
Other name(s): S-adenosyl-L-methionine:elongation factor 2 methyltransferase; diphthine methyltransferase
Systematic name: S-adenosyl-L-methionine:2-(3-carboxy-3-aminopropyl)-L-histidine methyltransferase
Comments: 2-[3-Carboxy-3-(methylammonio)propyl]-L-histidine and the corresponding dimethyl compound can also act as acceptors; the trimethylated product, diphthine, is converted into diphthamide by EC 6.3.2.22 diphthine—ammonia ligase.
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]