Substrate‐induced conformational changes in Escherichia coli arginyl–tRNA synthetase observed by 19F NMR spectroscopy

[摘要]

The ¹⁹F nuclear magnetic resonance (NMR) spectra of 4-fluorotryptophan (4-F-Trp)-labeled Escherichia coli arginyl–tRNA synthetase (ArgRS) show that there are distinct conformational changes in the catalytic core and tRNA anticodon stem and loop-binding domain of the enzyme, when arginine and tRNA^Arg are added to the unliganded enzyme. We have assigned five fluorine resonances of 4-F-Trp residues (162, 172, 228, 349 and 446) in the spectrum of the fluorinated enzyme by site-directed mutagenesis. The local conformational changes of E. coli ArgRS induced by its substrates observed herein by ¹⁹F NMR are similar to those of crystalline yeast homologous enzyme.

[学科分类] 生物化学/生物物理

[关键词] Aminoacyl–tRNA synthetase;tRNA2 Arg;Arginine;ATP;4-fluorotryptophan;Escherichia coli;aaRS;aminoacyl-tRNA synthetase;ArgRS;arginyl-tRNA synthetase;4-F-Trp;4-fluorotryptophan;FWT;4-F-Trp-labeled E. coli ArgRS;tRNA2 Arg;transfer RNA isoacceptor for arginine(ACG)