Modomics - A Database of RNA Modifications

ID Card:

Full name: Dimethyladenosine transferase 1, mitochondrial
Synonym: DIMT1, h-mtTFB1
GI: 74751555
Orf: CGI-75
COG: COG0030
UniProt: Q8WVM0
Structures: | |
Enzyme type: methyltransferase

Protein sequence:



h-mtTFB1 was first decribed as a nuclear-encoded mitochondrial transcription factor, but this protein has a dual function: acts as a mitochondrial transcription factor and an rRNA-modification enzyme. It methylates a conserved tandem A's (positions 1518, 1519, E. coli numbering) in the loop of a hairpin near the 3'-end of bacterial small subunit rRNA (as bacterial RsmA, formely KsgA). It was shown that the homologous sequence in the human mitochondrial 12S molecule is similarly modified. A second h-mtTFB2 also exists that is less efficient at methylating rRNA than h-mtTFB1. AdoMet is probably the methyl group donor. The structure of probable human cytosolic dimethyladenosine transferase has been solved (PDB id: 1ZQ9)


Title Authors Journal Details PubMed Id DOI
Human mitochondrial transcription factor B1 methylates ribosomal RNA at a conserved stem-loop. Seidel-Rogol BL, McCulloch V, Shadel GS Nat Genet [details] 12496758 -
Comprehensive phylogenetic analysis of evolutionarily conserved rRNA adenine dimethyltransferase suggests diverse bacterial contributions to the nucleus-encoded plastid proteome. Park AK, Kim H, Jin HJ Mol Phylogenet Evol [details] 19017544 -
Evidence for an early gene duplication event in the evolution of the mitochondrial transcription factor B family and maintenance of rRNA methyltransferase activity in human mtTFB1 and mtTFB2. Cotney J, Shadel GS J Mol Evol [details] 17031457 -