Independent saturation of three TrpRS subsites generates a partially assembled state similar to those observed in molecular simulations.
Laowanapiban, P., Kapustina, M., Vonrhein, C., Delarue, M., Koehl, P., Carter, C.W.(2009) Proc Natl Acad Sci U S A 106: 1790-1795
- PubMed: 19174517 
- DOI: https://doi.org/10.1073/pnas.0812752106
- Primary Citation of Related Structures:  
3FHJ, 3FI0 - PubMed Abstract: 
Two new crystal structures of Bacillus stearothermophilus tryptophanyl-tRNA synthetase (TrpRS) afford evidence that a closed interdomain hinge angle requires a covalent bond between AMP and an occupant of either pyrophosphate or tryptophan subsite. They also are within experimental error of a cluster of structures observed in a nonequilibrium molecular dynamics simulation showing partial active-site assembly. Further, the highest energy structure in a minimum action pathway computed by using elastic network models for Open and Pretransition state (PreTS) conformations for the fully liganded TrpRS monomer is intermediate between that simulated structure and a partially disassembled structure from a nonequilibrium molecular dynamics trajectory for the unliganded PreTS. These mutual consistencies provide unexpected validation of inferences drawn from molecular simulations.
Organizational Affiliation: 
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA.