Protein Summary

CmoB from Escherichia coli

Full name: tRNA 5-methoxyuridine(34) synthase
Synonym: YecP
GI: 3025152
Orf: b1871
COG: COG2230
UniProt: P76291
Structures: | 4QNX | 4QNU | 4QNV |
Enzyme type: carboxymethyltransferase
Position of modification - modification: t:34 - cmo5U
t:34 - mcmo5U


In E. coli CmoB is involved in conversion of ho5U to cmo5U (addition of carboxymethyl group) in tRNA. It catalyzes the transfer of the carboxymethyl group from carboxy-S-adenosyl-L-methionine (Cx-SAM) onto ho5U. Cx-SAM is generated from S-AdoMet and prephenate by CmoA. Null mutation of CmoA results in the accumulation of tRNA containing ho5U34 and mo5U34 (since CmoB can catalyze methyl group transfer from SAM in the absence of Cx-SAM generated by CmoA). A metabolic link exists between the biosynthesis of cmo5U and the biosynthesis of aromatic amino acids Tyr and Phe via the chorismic acid.

Protein sequence:


Enzymatic activities

Reaction Substrate Type Position
ho5U:mo5U tRNA (t)   34
ho5U:cmo5U tRNA (t)   34


Title Authors Journal Details PubMed Id DOI
The modified wobble nucleoside uridine-5-oxyacetic acid in tRNAPro(cmo5UGG) promotes reading of all four proline codons in vivo. Nasvall SJ, Chen P, Bjork GR RNA [details] 15383682 -
The wobble hypothesis revisited: uridine-5-oxyacetic acid is critical for reading of G-ending codons. Nasvall SJ, Chen P, Bjork GR RNA [details] 17942742 -
A novel link between the biosynthesis of aromatic amino acids and transfer RNA modification in Escherichia coli. Bjork GR J Mol Biol [details] 6160251 -
Structure-guided discovery of the metabolite carboxy-SAM that modulates tRNA function. Kim J, Xiao H, Bonanno JB, Kalyanaraman C, Brown S, Tang X, Al-Obaidi NF, Patskovsky Y, Babbitt PC, Jacobson MP, Lee YS, Almo SC... Nature [details] 23676670 -
S-Adenosyl-S-carboxymethyl-L-homocysteine: a novel cofactor found in the putative tRNA-modifying enzyme CmoA. Byrne RT, Whelan F, Aller P, Bird LE, Dowle A, Lobley CM, Reddivari Y, Nettleship JE, Owens RJ, Antson AA, Waterman DG... Acta Crystallogr D Biol Crystallogr [details] 23695253 -
Determinants of the CmoB carboxymethyl transferase utilized for selective tRNA wobble modification. Kim J, Xiao H, Koh J, Wang Y, Bonanno JB, Thomas K, Babbitt PC, Brown S, Lee YS, Almo SC... Nucleic Acids Res [details] 25855808 -



Last modification of this entry: 2015-04-21 16:16:02.741652
Edited by a user: magda
Edited content: Changed enzyme_type.