This clade of sequences is closely related to MiaB, a modifier of isopentenylated adenosine-37 of certain eukaryotic and bacterial tRNAs (see TIGR01574). Sequence alignments suggest that this equivalog performs the same chemical transformation as MiaB, perhaps on a different (or differently modified) tRNA base substrate. This clade is a member of a subfamily (TIGR00089) and spans the archaea and eukaryotes. The only archaeal miaB-like genes are in this clade, while eukaryotes have sequences described by this model as well as ones falling within the scope of the MiaB equivalog model. [Protein synthesis, tRNA and rRNA base modification]