Figure 3. A. Projection of H8-L-H9 motifs in bacterial GluRSs on the PC1-PC2 plane. The GluRSs are annotated by their tRNAGlx-specificity (D, ND, T1 or T2) and bacterial class: non-proteo or proteo (α-, β-, γ-, δ-, ε-). Two clusters (A, B) correspond to proteobacteria (with different tRNAGlx-specificity) while cluster C is dominated by non-proteobacteria. B. Projection of H8-L -H9 motifs in proteobacterial GluRSs on the PC1-PC2 plane. The vertical broken line separates tRNAGln-discriminatory and tRNAGln-nondiscriminatory bacteria. C.Projection of H8-L -H9 motifs in non-proteobacterial GluRSs on the PC1-PC2 plane. tRNAGln-discriminatory and tRNAGln-nondiscriminatory GluRSs are colored red and blue, respectively. D . H8-L -H9 motifs in GluRS1 (red) and GluRS2 (blue) from hyperthermophilic bacteria projected on the PC1-PC2 plane. E. H8-L -H9 motifs in D-GluRS (red) and ND-GluRS (blue) from firmicutes projected on the PC1-PC2 plane.