Modification of the alpha-subunit of phenylalanyl-tRNA synthetase from E. coli MRE-600 with N-chlorambucilyl-phenylalanyl-tRNA
Lavrik, O.I.; Khovyreva, S.N.
Biokhimiia 44(3): 570-572
L-Phenylalanyl-tRNA synthetase from E. coli MRE-600 (EC 220.127.116.11) was alkylated with N-chlorambucilyl-[14C] phenylalanyl-tRNA. After removal of the affinity reagent tRNA moiety bp alkaline hydrolysis of the ester bond between the N-chlorambucilyl-phenylalanyl residue and the 3'-end of tRNA, The enzyme was dissociated into subunits in the presence of SDS. Separation of the subunits was performed by SDS electrophoresis. The bulk of the radioactivity of the N-chlorambucilyl-[14C] phenylalanyl residue was found at the position of the alpha-subunit of the enzyme. The results obtained are consistent with a specific binding of the phenylalanyl-tRNA analog to the alpha-subunit of the enzyme followed by covalent binding of the N-chlorambucilyl-phenylalanyl moiety to the protein.