Crystal structures of Eco-GluRS
The crystal structure of Eco- GluRS was solved after initial phase determination by molecular replacement method, using the structure ofThermosynococcus elongates GluRS (Tel -GluRS; pdb ID: 2cfo (6)) as the search model. The final structural model of Eco -GluRS (Figure 1B) could be refined to 3.3 Å resolution with Rwork = 24.9 % and Rfree = 29.0 % (Table 1). The crystallographic asymmetric unit contained two nearly identical molecules of Eco -GluRS (r.m.s.d. 0.62 Å over all the C-alpha atoms), bound to one zinc ion and one L-glu molecule. All residues of Eco -GluRS were visible in the electron density map, except Glu117 in chain B; side chain atoms in residues 110-114, 129, 377-381, 392 of chain A and 112, 117, 118, 126-132, 136, 423 of chain B were not resolved clearly. Like other bacterial GluRS, Eco -GluRS showed an elongated structure (110 Å long and 39 Å wide) consisting of the N-terminal catalytic domain and the C-terminal anticodon-binding domain.