Crystals of Thermus thermophilus tRNAAsp Complexed with its Cognate Aspartyl-tRNA Synthetase Have a Solvent Content of 75%. Comparison with Other Aminoacylation Systems

Abstract

Thermus thermophilus tRNAAsp, purified from a non-recombinant source, has been crystallized in a complex with its cognate dimeric (α2) aspartyl-tRNA synthetase. Crystals diffract to 2.9 Å resolution and belong to space group P63 with cell parameters a = b = 258, c = 90.9 Å. The crystals contain one aspartyl-tRNA synthetase dimer and two tRNA molecules in the asymmetric unit, corresponding to a Vm of 4.85 Å3 Da−1 and 75% solvent content. When compared with those obtained for globular proteins these values are high, but fall within the range observed for other aminoacyl-tRNA synthetases, either free or complexed with their tRNAs. A comparative survey is presented here.