PMID:9164483
| Citation |
Uematsu, N, Eda, S and Yamamoto, K (1997) An Escherichia coli topB mutant increases deletion and frameshift mutations in the supF target gene. Mutat. Res. 383:223-30 |
|---|---|
| Abstract |
We have improved a system to examine forward mutations that occurred in the supF gene of Escherichia coli placed on a multicopy plasmid. Using this system, we determined the mutational specificity for a topB deletion mutator in which topoisomerase III is hampered. The frequency of supF- mutations in topB strain was 4.9 x 10(-7), that is essentially the same as that in wild-type strain, 3.1 x 10(-7). Half the number of the supF- mutations were large deletions, where a specific deletion among a 10-base pair direct repeat dominated, but other types of deletions were also found. Most of the deletions were associated with the presence of directly repeated sequences capable of accounting for their endpoints. Frameshift mutations in topB strain also significantly increased compared with those of wild-type (17 vs. 2%). Base substitutions comprised 27% of the events, specificity of which in topB strain was the same as that in wild-type strain. The present data suggest that topB is a novel class of mutator that strongly induces repeated sequence dependent deletion mutagenesis and high frequencies of frameshift mutagenesis. |
| Links | |
| Keywords |
Base Sequence; DNA Primers; DNA Topoisomerases, Type I/genetics; DNA Topoisomerases, Type I/metabolism; DNA Transposable Elements; Escherichia coli/genetics; Escherichia coli/metabolism; Frameshift Mutation; Gene Deletion; Genes, Bacterial; Genes, Suppressor; Molecular Sequence Data; Mutagenesis; Plasmids; Point Mutation; RNA, Transfer/genetics |
| edit table |
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.