title: Covalent attachment of fluorescent probes to the X-base of Escherichia coli phenylalanine transfer ribonucleic acid.
abstract: tRNA PheE, coli was labeled with the N-hydroxysuccinimide esters of 1-dimethylaminonaphthalene-5-sulfonyl glycine and N-methylanthranilic acid through reaction with the amino acid moiety of its X-base, whereby yields of 66% and 24%, respectively, were obtained. The purified dimethylaminonaphthalene-sulfonate derivative could not be aminoacylated and was found to be a strong competitive inhibitor of phenylalanine-tRNA synthetase [Ki=8X10(-7) M]. The N-methylanthraniloyl derivative could be charged to an extent of 5% as compared to native tRNA Phe. The fluorescence emission spectra of the derivatives are indicative of a slightly hydrophobic environment for both fluorophores. The results suggest that the integrity of the polar amino acid group of the X-base is required for the maintenance of the biologically active conformation.
mesh_terms: D003619:Dansyl Compounds; D004926:Escherichia coli / Q000032:analysis*; D005998:Glycine; D007700:Kinetics; D010649:Phenylalanine; D010652:Phenylalanine-tRNA Ligase / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000302:isolation & purification; D013050:Spectrometry, Fluorescence
chemical_list: D003619:Dansyl Compounds; D012346:RNA, Transfer, Amino Acyl; D010649:Phenylalanine; D010652:Phenylalanine-tRNA Ligase; D005998:Glycine