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Non-standard amino acid recognition by Escherichia coli leucyl-tRNA synthetaseRecombinant E. coli leucyl-tRNA synthetase was screened for amino acid-dependent pyrophosphate exchange activity using noncognate aliphatic amino acids including norvaline, homocysteine, norleucine, methionine, and homoserine. [32P]-labeled reaction products were separated by thin layer chromatography using a novel solvent system and then quantified by phosphorimaging. Norvaline which differs from leucine by only one methyl group stimulated pyrophosphate exchange activity as did both homocysteine and norleucine to a lesser extent. The KM parameters for leucine and norvaline were measured to be 10 micromoles and 1.5 mM, respectively. Experiments are in progress to determine if norvaline is transferred to tRNA(Leu) and/or edited by a pre- or post-transfer mechanism.
Document ID
20040089262
Document Type
Reprint (Version printed in journal)
Authors
Martinis, S. A. (University of Houston TX 77204-5934, United States)
Fox, G. E.
Date Acquired
August 21, 2013
Publication Date
January 1, 1997
Publication Information
Publication: Nucleic acids symposium series
Volume: 36
ISSN: 0261-3166
Subject Category
Exobiology
Funding Number(s)
CONTRACT_GRANT: NAG5-4004
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Exobiology