H. Tran et al., ALTERED REPLICATION AND INVERTED REPEATS INDUCE MISMATCH REPAIR-INDEPENDENT RECOMBINATION BETWEEN HIGHLY DIVERGED DNAS IN YEAST, Molecular and cellular biology, 17(2), 1997, pp. 1027-1036
Replication, DNA organization, and mismatch repair (MMR) can influence
recombination. We examined the effects of altered replication due to
a mutation in the polymerase delta gene, long inverted repeats (LIRs)
in motifs similar to those in higher eukaryotes, and MMR on intrachrom
osomal recombination between highly diverged (28%) truncated genes in
Saccharomyces cerevisiae. A combination of altered replication and an
LIR increased recombination up to 700-fold, while each alone led to a
3- to 20-fold increase. Homeologous recombination was not altered by p
ms1, msh2, and msh3 mismatch repair mutations. Similar to our previous
observations for replication slippage-mediated deletions, there were
greater than or equal to 5-bp identical runs at the recombination brea
kpoints. We propose that the dramatic increase in recombination result
s from enhancement of the effects of altered replication by the LIR, l
eading to recombinationally active initiating structures. Such interac
tions predict replication-related, MMR-independent genome changes.