High frequencies of short frameshifts in poly-CA/TG tandem repeats borne by bacteriophage M13 in Escherichia coli K-12 - PubMed (original) (raw)

High frequencies of short frameshifts in poly-CA/TG tandem repeats borne by bacteriophage M13 in Escherichia coli K-12

G Levinson et al. Nucleic Acids Res. 1987.

Free PMC article

Abstract

Slipped-strand mispairing (SSM) may play an major role in repetitive DNA sequence evolution by generating large numbers of short frameshift mutations within simple tandem repeats. Here we examine the frequency and size spectrum of frameshifts generated within poly-CA/TG sequences inserted into bacteriophage M13 in Escherichia coli hosts. The frequency of detectable frameshifts within a 40 bp tract of poly-CA/TG is greater than one percent and increases more than linearly with length, being lower by a factor of four in a 22 bp target sequence. The frequency increases more than 13-fold in mutL and mutS host cells, suggesting that a high proportion of frameshift events are normally repaired by methyl-directed mismatch repair. Of the 87 sequenced frameshifts in this study, 96% result from deletion or insertion of only or two 2 bp repeat units. The most frequent events are 2 bp deletions, 2 bp insertions, and 4 bp deletions, the relative frequencies of these events being about 18:6:1.

PubMed Disclaimer

Similar articles

Cited by

References

    1. J Mol Biol. 1971 Nov 28;62(1):233-40 - PubMed
    1. Cell. 1980 Oct;21(3):653-68 - PubMed
    1. J Mol Biol. 1981 Jul 5;149(3):337-76 - PubMed
    1. J Mol Biol. 1983 Jun 5;166(4):557-80 - PubMed
    1. EMBO J. 1983;2(12):2117-22 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources