Figure 4.

Isopentenyl transferase assay. i6A target tRNAs of M. tb tRNA^LeuCAA, tRNA^PheGAA, tRNA^TrpCCA and tRNA^SerCGA were labeled internally with ³²P-Guanosine and incubated with immunoprecipitated MiaA in the presence or absence of the substrate DMAPP at 37^oC. 4A-D: tRNA fragment showing shift in migration indicating addition of i6A group. Shifted bands with A36A37A38 motif after T1 digestion are shown by the arrow, LeuCAA ACUCAAAACCCG, 12nt; PheGAA: AAAAG ,5nt; TrpCCA: UCUCCAAAACCG, 12nt; SerCGA: AAAG, 4nt