Catalysis of the reaction: dimethylallyl diphosphate + tRNA = diphosphate + tRNA containing 6-dimethylallyladenosine.
Comment:
Note that this activity was formerly know in GO and EC as 'tRNA isopentenyltransferase' (GO:0004811), but it is now known that dimethylallyl diphosphate, rather than isopentenyl diphosphate, is the substrate.
EC:2.5.1.75; MetaCyc:RXN0-6274; RHEA:26482; reactome:R-HSA-6784462 "TRIT1 transfers dimethylallyl group to adenosine-37 of tRNAs"; reactome:R-HSA-6787567 "TRIT1 transfers dimethylallyl group to adenosine-37 of tRNA(Ser)"