Tolerance of DNA Mismatches in Dmc1 Recombinase-mediated DNA Strand Exchange.

BORGOGNO MARÍA V; MONTI MARIELA R; ZHAO W; SUNG P; ARGARAÑA CARLOS E; PEZZA ROBERTO J

JOURNAL OF BIOLOGICAL CHEMISTRY

AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Lugar: Bethesda, Maryland; Año: 2016 vol. 291 p. 4928 - 4928

0021-9258

ecombination between homologous chromosomes is required for the faithful meiotic segregation of chromosomes and leads to the generation of genetic diversity. The conserved meiosis-specific Dmc1 recombinase catalyzes homologousrecombination triggered by DNA double strand breaks through the exchange of parental DNA sequences. Although providing an efficient rate of DNA strand exchange between polymorphic alleles, Dmc1 must also guard against recombination between divergent sequences. How DNA mismatches affect Dmc1-mediated DNA strand exchange is not understood. We have used fluorescence resonance energy transfer to study the mechanism of Dmc1-mediated strand exchange between DNA oligonucleotides with different degrees of heterology. The efficiency of strand exchange is highly sensitive to the location, type, and distribution of mismatches. Mismatches near the 3 end of the initiating DNA strand have a small effect, whereas most mismatches near the 5 end impede strand exchange dramaticall