This family consists of several bacterial tRNA-(MS(2)IO(6)A)-hydroxylase (MiaE) proteins. The modified nucleoside 2-methylthio-N-6-isopentenyl adenosine (ms2i6A) is present at position 37 (3' of the anticodon) of tRNAs that read codons beginning with U except tRNA(I,V Ser) in Escherichia coli. Salmonella typhimurium 2-methylthio-cis-ribozeatin (ms2io6A) is found in tRNA, probably in the corresponding species that have ms2i6A in E. coli. The miaE gene is absent in E. coli, a finding consistent with the absence of the hydroxylated derivative of ms2i6A in this species [1-2].

1: Isolation of the gene (miaE) encoding the hydroxylase involved in the synthesis of 2-methylthio-cis-ribozeatin in tRNA of Salmonella typhimurium and characterization of mutants. Persson BC, Bjork GR; J Bacteriol 1993;175:7776-7785. PMID:8253666

2: tRNA-modifying MiaE protein from Salmonella typhimurium is a nonheme diiron monooxygenase. Mathevon C, Pierrel F, Oddou JL, Garcia-Serres R, Blondin G, Latour JM, Menage S, Gambarelli S, Fontecave M, Atta M; Proc Natl Acad Sci U S A. 2007;104:13295-13300. PMID:17679698