Crystal structure of the aspartyl-tRNA synthetase from Entamoeba histolytica.
Merritt, E.A., Arakaki, T.L., Larson, E.T., Kelley, A., Mueller, N., Napuli, A.J., Zhang, L., Deditta, G., Luft, J., Verlinde, C.L., Fan, E., Zucker, F., Buckner, F.S., Van Voorhis, W.C., Hol, W.G.(2010) Mol Biochem Parasitol 169: 95-100
- PubMed: 19874856 
- DOI: https://doi.org/10.1016/j.molbiopara.2009.10.005
- PubMed Abstract: 
The crystal structure of the aspartyl-tRNA synthetase from the eukaryotic parasite Entamoeba histolytica has been determined at 2.8Aresolution. Relative to homologous sequences, the E. histolytica protein contains a 43-residue insertion between the N-terminal anticodon binding domain and the C-terminal catalytic domain. The present structure reveals that this insertion extends an arm of the hinge region that has previously been shown to mediate interaction of aspartyl-tRNA synthetase with the cognate tRNA D-stem. Modeling indicates that this Entamoeba-specific insertion is likely to increase the interaction surface with the cognate tRNA(Asp). In doing so it may substitute functionally for an RNA-binding motif located in N-terminal extensions found in AspRS sequences from lower eukaryotes but absent in Entamoeba. The E. histolytica AspRS structure shows a well-ordered N-terminus that contributes to the AspRS dimer interface.
Organizational Affiliation: 
Department of Biochemistry, University of Washington, Mailstop 357742, Seattle, WA 98195, USA. merritt@u.washington.edu