Figure 8.

Effect of acetylation of Lys on the Leu activation and aminoacylation activities of EcArgRS. A, sequence alignment of ArgRSs from various species in regions homologous to Lys¹²⁶ and Lys⁴⁰⁸ of EcArgRS. The abbreviations are the same as those in Fig. 4, except for two species (Se, S. enterica; Sc, S. cerevisiae). B, Arg activation of EcArgRS-K^Acs. C, aminoacylation of EcArgRS-K^Acs resembling that of the K-Q mutants. D, orientation of PhArgRS Lys¹³² (homologous to Lys¹²⁶ in EcArgRS) relative to the conserved HIGH motif (HMGH in PhArgRS, depicted in dark blue). E, closer view of the interaction between PhArgRS Lys⁴⁵⁵ (corresponding to Lys⁴⁰⁸ in EcArgRS) and PhtRNA^Arg A38. The results are the averages and standard deviations from three independent experiments.