Escherichia coli Frameshift Mutation Rate Depends on rate depends on the chromosomal context but not on the GATC content near the mutation site

MARTINA MA; CORREA EME; ARGARAÑA CE; BARRA JL

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2012 vol. 7 p. 1 - 1

ifferent studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent mann