Crystallization and X-ray analysis of human cytoplasmic phenylalanyl-tRNA synthetase

摘要

Human cytosolic phenylalanyl-tRNA synthetase (hcPheRS) is responsible for the covalent attachment of phenylalanine to its cognate tRNA^Phe. Significant differences between the amino-acid sequences of eukaryotic and prokaryotic PheRSs indicate that the domain composition of hcPheRS differs from that of the Thermus thermophilus analogue. As a consequence of the absence of the anticodon-recognizing B8 domain, the binding mode of tRNA^Phe to hcPheRS is expected to differ from that in prokaryotes. Recombinant hcPheRS protein was purified to homogeneity and crystallized. The crystals used for structure determination diffracted to 3.3 Å resolution and belonged to space group C2, with unit-cell parameters a = 362.9, b = 213.6, c = 212.7 Å, β = 125.2°. The structure of hcPheRS was determined by the molecular-replacement method in combination with phase information from multiwavelength anomalous dispersion.