Disease relevance of trmA

• Cloning and restriction mapping of the trmA gene coding for transfer ribonucleic acid (5-methyluridine)-methyltransferase in Escherichia coli K-12 [1].
• These results and comparison with lambda dargECBH transducing phages established the gene order: argECBH trmA bfe in the 88-min region of the E. coli chromosomal map [1].

High impact information on trmA

• The enzyme tRNA(m5U54)methyltransferase [S-adenosyl-L-methionine:tRNA (uracil-5-)-methyltransferase, EC 2.1.1.35] (the trmA gene product) catalyzes S-adenosylmethionine-dependent methylation of the uracil in position 54 (T psi C loop) in all Escherichia coli tRNAs to form m5U [2].
• One of the most abundant modified nucleosides in tRNA is 5-methyluridine (m5U or rT, ribothymidine) [2].
• The formation of these modified nucleosides is catalyzed by the products of genes trmH (Gm18), trmA (m(5)U54), and truB (Psi55) [3].
• Physical map of the oxyR-trmA region (minute 89.3) of the Escherichia coli chromosome [4].
• The trmA and the btuB (encoding the vitamin B12 outer membrane receptor protein) promoters are divergent promoters separated by 102 bp between the transcriptional start sites [5].

Chemical compound and disease context of trmA

• This plasmid carries the trmA gene of E. coli, which is necessary for the formation of 5-methyluridine (m5U,ribothymidine) present in all transfer ribonucleic acid (tRNA) chains of the organism so far sequenced [1].

Biological context of trmA

• The trmA gene is transcribed as a monocistronic operon, and the 3' end of the transcript is shown to be located downstream from a dyad symmetry region not followed by a poly(U) stretch [5].
• A gene located close to trmA (the structural cistron for the methyltransferase that produces m5U in tRNA), however, was found to reduce the growth rates significantly, depending on the medium and the temperature of cultivation [6].

Associations of trmA with chemical compounds

• Furthermore, the trmA5 mutation was shown to be recessive, in agreement with the notion that the trmA gene is the structural gene for the transfer tibonucleic acid (5-methyluridine) methyltransferase [7].

Regulatory relationships of trmA

• The temperature sensitivity of truB mutants could be enhanced by combination with a mutation in the trmA gene, encoding an m(5)U-methyltransferase, modifying the universal U54 tRNA nucleoside, but not by mutations in trmH, encoding the enzyme catalysing the formation of Gm18 [8].

Other interactions of trmA

• This gene has been designated mor and is located at 89 minutes on the E. coli chromosome map between the argECBH operon and the trmA gene [9].

References