Available crystal structures of bacterial GluRSs
Since the H8-L -H9 sequences separated proteobacterial GluRSs into two clusters which correlated well with their tRNAGln-specificities, we explored the structural differences of this motif in the available crystal structures of bacterial GluRSs (Table S2). Other than Eco (D-)-GluRS (this work, pdb ID: 8i9i), there are five more crystal structures of proteobacterial GluRSs: Sml -GluRS (Stenotrophomonas maltophilia GluRS, pdb ID: 7k86), Xop (D-)-GluRS (Xanthomonas oryzae GluRS, pdb ID: 5h4v), Bte (D+)-GluRS (Burkholderia thailandensisGluRS; pdb ID: 4g6z), Hpy -T1-GluRS (Helicobacter pyloriGluRS, pdb ID: 6b1p) and Pae (D+)-GluRS (Pseudomonas aeruginosa GluRS, pdb ID: 5tgt). The H8-L -H9 motifs were also analyzed from seven available non-proteobacterial crystal structures:Tma (T1)-GluRS (T. maritima GluRS, pdb ID: 6b1p),Bbu (ND)-GluRS (B. burgdorferi GluRS, pdb ID: 6b1p),Mtu (ND)-GluRS (Mycobacterium tuberculosis GluRS, pdb ID: 6b1p), Emg -(D+)-GluRS (Elizabethkingia meningosepticaGluRS, pdb ID: 6b1p), Tma (T2)-GluRS (Thermotoga maritimaGluRS, pdb ID: 6b1p), Tth (D+)-GluRS (Thermus thermophilusGluRS, pdb ID: 6b1p) and Tel (ND)-GluRS (T. elongatesGluRS, pdb ID: 2cfo).