FIG. 1.

Gel autoradiogram of the avilamycin footprint in domain V of 23S rRNA after binding to ribosomes, showing DMS modifications detected by reverse transcriptase of rRNA. U, C, G, and A, dideoxy sequencing lanes; No mod., chemically unmodified rRNA; No drug, chemically modified ribosomes in the absence of avilamycin. The triangle denotes modification in the presence of 1.3, 6.6, 13.2, 66, 132, and 264 μg of avilamycin per ml. Positions with altered reactivities are indicated by arrows. Reverse transcriptase stops one nucleotide before the corresponding nucleotide in the sequencing tracks.