Domains of phenylalanyl-tRNA synthetase from Thermus thermophilus required for aminoacylation

Abstract

The contribution of entire domains or particular amino acid residues of the phenylalanyl-tRNA synthetase (FRS) from Thermus thermophilus to the interaction with tRNA Phe was studied. Removal of domain 8 of the β subunit resulted in drastic reduction of the dissociation constant of the FRS·tRNA Phe complex. Neither the removal of arginine 2 of the β subunit, which makes the only major contact between domains β1–5 and the tRNA, nor the replacement of the conserved proline 473 by glycine had an influence on the aminoacylation activity of the FRS. Thus, the body comprising domains 1–5 of the β subunit may not be essential for efficient aminoacylation of tRNA Phe by the FRS and rather be involved in other functions.