Identification of potential amino acid residues supporting anticodon recognition in yeast methionyl-tRNA synthetase

Abstract

Sequence comparisons among methionyl-tRNA synthetases from different organisms reveal only one block of homology beyond the lasts β strand of the mononucleotide fold. We have introduced a series of semi-conservative amino acid replacements in the conserved motif of yeast methionyl-tRNA synthetase. The results indicate that replacements of two polar residues (Asn 584 and Arg 588) affected specifically the aminoacylation reaction. The location of these residues in the tertiary structure of the enzyme is compatible with a direct interaction of the amino acid side-chains with the tRNA anticodon.