title: [Modification of one tRNA recognition site of phenylalanyl-tRNA synthetase from E. coli MRE-600 with N-chlorambucilyl-phenylalanyl-tRNA].
abstract: Affinity labelling of phenylalanyl-tRNA synthetase from E. coli MRE-600 with N-chlorambucilyl-phenylalanyl-tRNA results in a binding of 1 mole of the reagent per 1 mole of the enzyme. Exhaustive alkylation of phenylalanyl-tRNA synthetase completely blocks the aminoacylation and partially inhibits the reaction of ATP--[32P]pyrophosphate exchange. Removal of the tRNA moiety of the reagent by hydrolysis of the ester bond N-chlorambucilyl-phenylalanine and terminal adenosine does not result in a restoration of ATP--[32P]pyrophosphate exchange and aminoacylation activity. The latter result may testify a chemical modification of amino acid residues essential for enzymatic activity. Possibility of blocking one of the two tRNA binding sites is discussed.
mesh_terms: D000255:Adenosine Triphosphate; D000345:Affinity Labels; D000478:Alkylation; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism; D001665:Binding Sites; D002699:Chlorambucil / Q000031:analogs & derivatives*; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D008433:Mathematics; D010649:Phenylalanine; D010652:Phenylalanine-tRNA Ligase / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl
chemical_list: D000345:Affinity Labels; D012346:RNA, Transfer, Amino Acyl; D002699:Chlorambucil; D010649:Phenylalanine; D000255:Adenosine Triphosphate; D000604:Amino Acyl-tRNA Synthetases; D010652:Phenylalanine-tRNA Ligase
vernacular_title: Blokirovanie tRNK-uznaiushchego uchastka fenilalanil-tRNK-sintetazy iz Escherichia coli MRE-600 S pomoshch'iu N-khlorambutsilil-fenilalanil-tRNK.