Format

Send to:

Choose Destination
See comment in PubMed Commons below
Biochemistry. 1996 Nov 26;35(47):14725-33.

Crystal structures of three misacylating mutants of Escherichia coli glutaminyl-tRNA synthetase complexed with tRNA(Gln) and ATP.

Author information

  • 1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA.

Abstract

Three previously described mutant Escherichia coli glutaminyl-tRNA synthetase (GlnRS) proteins that incorrectly aminoacylate the amber suppressor derived from tRNATyr (supF) with glutamine were cocrystallized with wild-type tRNAGln and their structures determined. In two of the mutant enzymes studied, Asp235, which contacts base pair G3-C70 in the acceptor stem, has been changed to asparagine in GlnRS7 and to glycine in GlnRS10. These mutations result in changed interactions between Asn235 of GlnRS7 and G3-C70 of the tRNA and an altered water structure between Gly235 of GlnRS10 and base pair G3-C70. These structures suggest how the mutant enzymes can show only small changes in their ability to aminoacylate wild-type cognate tRNA on the one hand and yet show a lack of discrimination against a noncognate U3-A70 base pair on the other. In contrast, the change of Ile129 to Thr in GlnRS15 causes virtually no change in the structure of the complex, and the explanation for its ability to misacylate supF is unclear.

PMID:
8942633
[PubMed - indexed for MEDLINE]

LinkOut - more resources

Full Text Sources

Other Literature Sources

Molecular Biology Databases

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society
    Loading ...
    Write to the Help Desk