Discrimination of tRNALeu isoacceptors by the insertion mutant of Escherichia coli leucyl-tRNA synthetase.

Journal Article (Journal Article)

A variant (LeuRS-A) of Escherichia coli leucyl-tRNA synthetase (LeuRS) carrying a 40-residue duplication in its connective peptide 1 (CP1) has a 3-fold lower specificity for than for, whereas wild-type LeuRS has the same specificity for these two isoacceptors. The replacement of the acceptor stem of with yields a chimeric tRNA(Leu) for which wild-type LeuRS has the same specificity as it does for the two normal isoacceptors mentioned, but for which LeuRS-A has a reduced specificity similar to that for, indicating a difference between these two acceptor stems. LeuRS-A is slightly less stable than the native enzyme. Wild-type LeuRS and LeuRS-A have almost same K(d) value for their interaction with as determined by fluorescence quenching. No difference was detected between these two proteins by CD and fluorescence spectroscopy. These results show that LeuRS-A can discriminate between the two isoacceptors of tRNA(Leu).

Full Text

Duke Authors

Cited Authors

  • Li, T; Li, Y; Guo, N; Wang, E; Wang, Y

Published Date

  • July 13, 1999

Published In

Volume / Issue

  • 38 / 28

Start / End Page

  • 9084 - 9088

PubMed ID

  • 10413482

International Standard Serial Number (ISSN)

  • 0006-2960

Digital Object Identifier (DOI)

  • 10.1021/bi9901984


  • eng

Conference Location

  • United States