@article {2019|2064,
	title = {Slow extension of the invading DNA strand in a D-loop formed by RecA-mediated homologous recombination may enhance recognition of DNA homology},
	journal = {J Biol Chem},
	volume = {294},
	year = {2019},
	month = {May},
	pages = {8606-8616},
	abstract = {<p>DNA recombination resulting from RecA-mediated strand exchange aided by RecBCD proteins often enables accurate repair of DNA double-strand breaks. However, the process of recombinational repair between short DNA regions of accidental similarity can lead to fatal genomic rearrangements. Previous studies have probed how effectively RecA discriminates against interactions involving a short similar sequence that is embedded in otherwise dissimilar sequences but have not yielded fully conclusive results. Here, we present results of in vitro experiments with fluorescent probes strategically located on the interacting DNA fragments used for recombination. Our findings suggest that DNA synthesis increases the stability of the recombination products. Fluorescence measurements can also probe the homology dependence of the extension of invading DNA strands in D-loops formed by RecA-mediated strand exchange. We examined the slow extension of the invading strand in a D-loop by DNA polymerase (Pol) IV and the more rapid extension by DNA polymerase LF-Bsu We found that when DNA Pol IV extends the invading strand in a D-loop formed by RecA-mediated strand exchange, the extension afforded by 82 bp of homology is significantly longer than the extension on 50 bp of homology. In contrast, the extension of the invading strand in D-loops by DNA LF-Bsu Pol is similar for intermediates with \&ge;50 bp of homology. These results suggest that fatal genomic rearrangements due to the recombination of small regions of accidental homology may be reduced if RecA-mediated strand exchange is immediately followed by DNA synthesis by a slow polymerase.</p>
},
	keywords = {cooperativity, DNA damage, DNA polymerase, DNA recombination, double-strand break (DSB), fluorescence resonance energy transfer (FRET), heteroduplex formation, molecular dynamics, RecA, strand displacement synthesis},
	doi = {10.1074/jbc.RA119.007554},
	author = {Lu, Daniel and Danilowicz, Claudia and Tashjian, Tommy F and Chantal Pr{\'e}vost and Godoy, Veronica G and Prentiss, Mara}
}
@article {2015|1641,
	title = {Structure/function relationships in RecA protein-mediated homology recognition and strand exchange},
	journal = {Crit. Rev. Biochem. Mol. Biol.},
	volume = {50},
	year = {2015},
	pages = {453{\textendash}76},
	abstract = {RecA family proteins include RecA, Rad51, and Dmc1. These recombinases are responsible for homology search and strand exchange. Homology search and strand exchange occur during double-strand break repair and in eukaryotes during meiotic recombination. In bacteria, homology search begins when RecA binds an initiating single-stranded DNA (ssDNA) in the primary DNA-binding site to form the presynaptic filament. The filament is a right-handed helix, where the initiating strand is bound deep within the filament. Once the presynaptic filament is formed, it interrogates nearby double-stranded DNA (dsDNA) to find a homologous sequence; therefore, we provide a detailed discussion of structural features of the presynaptic filament that play important functional roles. The discussion includes many diagrams showing multiple filament turns. These diagrams illustrate interactions that are not evident in single turn structures. The first dsDNA interactions with the presynaptic filament are insensitive to mismatches. The mismatch insensitive interactions lead to dsDNA deformation that triggers a homology testing process governed by kinetics. The first homology test involves {\^a}{\textonequarter}8 bases. Almost all interactions are rejected by this initial rapid test, leading to a new cycle of homology testing. Interactions that pass the initial rapid test proceed to a slower testing stage. That slower stage induces nonhomologous dsDNA to reverse strand exchange and begin a new cycle of homology testing. In contrast, homologous dsDNA continues to extend the heteroduplex strand-exchange product until ATP hydrolysis makes strand exchange irreversible.},
	keywords = {Double-strand break repair, meiosis, meiotic recombination, Rad51, recombinase},
	doi = {10.3109/10409238.2015.1092943},
	author = {Prentiss, Mara and Chantal Pr{\'e}vost and Danilowicz, Claudia}
}
