Phenylalanyl-tRNA synthetase fromE. coli MRE-600: Localization of the phenylalanine binding sites on the subunits by affinity reagents

Abstract

The phenylalanine and the phenylalanyl-tRNA^Phe binding sites on the subunits of phenylalanyl-tRNA synthetase fromE.coli MRE-600 were localized using p-azidoanilidate of [¹⁴C]phenylalanine and N-bromoacetyl[¹⁴C]phenylalanyl-tRNA^Phe. The phenylalanine recognizing site was shown to be situated on the α subunit of the enzyme in close proximity to the contact region of the α and β subunits and the phenylalanyl-tRNA^Phe recognizing site on the β subunit. Transfer of the aminoacyl moiety from the α subunit to the β subunit of the enzyme was assumed to take place in the process of catalysis of the aminoacylation reaction.