PMID:10047479

From EcoliWiki
Jump to navigation Jump to search
Citation

McClain, WH, Gabriel, K, Bhattacharya, S, Jou, YY and Schneider, J (1999) Functional compensation by particular nucleotide substitutions of a critical G*U wobble base-pair during aminoacylation of transfer RNA. J. Mol. Biol. 286:1025-32

Abstract

Expression of the genetic code depends on precise tRNA aminoacylation by cognate aminoacyl-tRNA synthetase enzymes. The G.U wobble base-pair in the acceptor helix of Escherichia coli alanine tRNA is the primary aminoacylation determinant of this molecule. Previous work on the process of synthetase recognition of the G.U pair showed that replacing G.U by a G.C Watson-Crick base-pair inactivates alanine acceptance by the tRNA, but that C.A and G.A wobble pair replacements preserve acceptance. Work by another group reported that the effects of a G.C replacement were reversed by a distal wobble base-pair in the anticodon helix. This result is potentially interesting because it suggests that distant regions in alanine tRNA are functionally coupled during synthetase recognition and more generally because recognition determinants of many other tRNAs lie in both the acceptor helix and anticodon helix region. Here, we have conducted an extensive in vivo analysis of the distal wobble pair in alanine tRNA and report that it does not behave like a compensating mutation. Restoration of alanine acceptance was not detected even when the synthetase enzyme was overproduced. We discuss the previous experimental evidence and suggest how the distal wobble pair was incorrectly analyzed. The available data indicate that all principal recognition determinants of alanine tRNA lie in the molecule's acceptor helix.

Links

PubMed Online version:10.1006/jmbi.1999.2542

Keywords

Acylation; Alanine/chemistry; Amino Acyl-tRNA Synthetases/metabolism; Base Pairing; Base Sequence; Electrophoresis, Polyacrylamide Gel; Escherichia coli/genetics; Guanine/chemistry; Molecular Sequence Data; Nucleic Acid Conformation; Point Mutation; RNA, Transfer, Amino Acyl/chemistry; RNA, Transfer, Amino Acyl/genetics; RNA, Transfer, Amino Acyl/metabolism; Uridine/chemistry

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.