Figure 5. A . Interaction of Eco -GluRS H8-L -H9 α-[>>t ] conformation with the augmented D-helix of Tth -tRNAGlu. TheTth -GluRS-tRNAGlu structure (pdb ID: 2cv0) was used as the template and Eco -GluRS was superposed on the Tth -GluRS. B. Interaction of Eco -GluRS H8-L-H9 α-[>>t ] conformation with non-augmented D-helix of Eco -tRNAGln. TheEco -GlnRS-tRNAGln structure (pdb ID: 1gts) was used as the template and Eco -GluRS was superposed on theEco -GlnRS. Steric clashes between Eco -GluRS andEco -tRNAGln are highlighted by broken lines.C. Interaction of Eco -GluRS H8-L-H9 α-[>>t ] conformation with non-augmented D-helix of Eco -tRNAGln. TheTth -GluRS-tRNAGlu structure was used as the template; subsequently Eco -GluRS was superposed on theTth -GluRS and Eco -tRNAGln (pdb ID: 1gts) was superposed on Tth -tRNAGlu. D.Superposition of H8-L -H9 motifs in Eco -GluRS andHpy (T1)-GluRS (AlphaFold model and crystal structure). E288 ofPae -GluRS is shown in two rotameric states. E.Superposition of H8-L-H9 motifs in Eco -GluRS andPae -GluRS. E288 of Pae -GluRS is shown in two rotameric states. F. Structural superposition of H8-L-H9 motifs inEco -GluRS and 7 non-proteobacterial GluRSs (Figure 4A). Two non-proteobacterial GluRSs (MTU and BBU) exhibit the [>>t ] conformation while the rest adopt the [<<t ] conformation.