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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1-2
|
| pubmed:dateCreated |
1991-11-27
|
| pubmed:abstractText |
This paper describes the DNA sequence analysis of 729 independent spontaneous lacI- mutations. This total is comprised of 478 novel mutations and 251 previously described events, and therefore should allow a more comprehensive view of spontaneous mutation in Escherichia coli. The spectrum is dominated by a hotspot (71% of all events). Mutations at this site consist of related addition and deletion events involving a number of repetitive sequences. Here we discuss how the frequency and proportion of these events vary in different DNA repair-deficient genetic backgrounds. The distribution of non-hotspot events includes base substitutions (38%), deletions (35%), frameshifts (14%), duplications (4%) and insertion elements (4%). G:C----A:T events dominate among base substitutions, while G:C----C:G events are the least common; the remaining types of base substitution are equally represented. Among deletions, a significant number do not display repeated sequences at their endpoints (26/72). However, almost all multiply recovered events (15/17) possess repeated sequences capable of accounting for the deletion endpoints. Similarly, over half of all duplications recovered (5/7) display repeated endpoints. Single-base frameshifts are equally divided between A:T and G:C sites, in each case (-) 1 events occur 3-fold more frequently that (+) 1 events. A comparative analysis of each mutational class recovered to lacI- spectra available in a variety of DNA repair/metabolism-deficient strains is presented here in an attempt to assess possible contributions from chemical, physical and enzymic sources of damage.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:issn |
0027-5107
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
250
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
55-71
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:1944363-Base Sequence,
pubmed-meshheading:1944363-DNA, Bacterial,
pubmed-meshheading:1944363-DNA Repair,
pubmed-meshheading:1944363-Escherichia coli,
pubmed-meshheading:1944363-Frameshift Mutation,
pubmed-meshheading:1944363-Molecular Sequence Data,
pubmed-meshheading:1944363-Mutation
|
| pubmed:articleTitle |
Mechanisms of spontaneous mutation in DNA repair-proficient Escherichia coli.
|
| pubmed:affiliation |
Department of Biology, York University, Toronto, Ont., Canada.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|