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

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 subunit of the enzyme in close proximity to the contact region of the and subunits and the phenylalanyl-tRNA^Phe recognizing site on the subunit. Transfer of the aminoacyl moiety from the subunit to the subunit of the enzyme was assumed to take place in the process of catalysis of the aminoacylation reaction.