Exploring GpG bases next to anticodon in tRNA subsets

Transfer RNA (tRNA) structure, modifications and functions are evolutionary and established in bacteria, archaea and eukaryotes.Typically the tRNA modifications are indispensable for its stability and are required for decoding the mRNA into amino acids forprotein synthesis. A conserved methylation has been located on the anticodon loop specifically at the 37^th position and it is next tothe anticodon bases. This modification is called as m1G37 and it is catalyzed by tRNA (m¹G37) methyltransferase (TrmD). It isdeciphered that G37 positions occur on few additional amino acids specific tRNA subsets in bacteria. Furthermore, Archaea andEukaryotes have more number of tRNA subsets which contains G37 position next to the anticodon and the G residue are located atdifferent positions such as G36, G37, G38, 39, and G40. In eight bacterial species, G (guanosine) residues are presents at the 37^th and38^th position except three tRNA subsets having G residues at 36^th and 39^th positions. Therefore we propose that m1G37 modificationmay be feasible at 36^th, 37^th, 38^th, 39^th and 40^th positions next to the anticodon of tRNAs. Collectively, methylation at G residuesclose to the anticodon may be possible at different positions and without restriction of anticodon 3^rd base A, C, U or G.