FIG. 2.

Secondary-structure model of the central loop region of domain V of E. coli 23S rRNA. Small numbers are nucleotide positions in 23S rRNA, and large numbers are helix numbers. The avilamycin footprints are indicated by arrows. The corresponding positions of mutations in H. halobium selected with avilamycin (this study; indicated by circles) or evernimicin (7; indicated by red letters and circles) are marked. The helix 89 region is in green; the helix 91 region is in blue. (Adapted from Gutell Lab., comparative RNA web site http://www.rna.icmb.utexas.edu/.)