Figure 3 - Model of the bacterial type A RPR–tRNA complex.

Figure 3. Model of the bacterial type A RPR–tRNA complex. Docking of the tRNA on the RPR tertiary structure was based on spatial relationships predicted by biochemical data on the RPR–ptRNA complex. The acceptor-T stem stack straddles both the S- and C-domains; specific interactions between the TψC stem-loop of the substrate and the S-domain position the scissile phosphodiester linkage in a groove in the C-domain. Conserved nucleotides (A49 [P4], A213 [J5/15], and A313 [J2/4]) likely to form the active site are clustered around the cleavage site. This figure was kindly provided by Prof. Alfonso Mondragon, Northwestern University. (Reprinted, with permission, from Torres-Larios et al. 2005 [©Macmillan].)