FIG 2.
TGC selects for mutations on a loop of S10 that is in close proximity to the 16S rRNA and composes the TGC binding pocket. (A) Image of the crystal structure of TGC bound to the Thermus thermophilus ribosome (PDB 4G5T) (21). Labels on amino acids indicate positions on the loop of S10 where mutations were identified in Gram-positive species (red) or both Gram-positive and -negative species (blue). For clarity, the amino acid numbering corresponds to the E. coli S10 sequence, and only rRNA structure (gray) proximal to the loop is shown. The inset shows the entire structure of S10 with colored spheres at the α-carbon of residues where mutations where identified in Gram-positive (red) or both Gram-positive and -negative (blue) organisms. (B) Alignment of the T. thermophilus S10 sequence and the susceptible S10 sequences for species where mutations in S10 have been identified in response to TGC adaptation. The sequence logo shows the S10 consensus sequence. The black box outlines the residues that compose the loop structure (positions 53 to 61). The blue and red boxes outline the residues where mutations were identified in Gram-positive species (red) or both Gram-positive and -negative species (blue).