FIGURE 7.

Strand exchange kinetics with ATP and ATPγS. A, microhomology analysis of the φX174 plasmid DNA substrates showing the number of potential sites (count) at which a given length of φX174 ssDNA microhomology, ranging from 5 to 12 bp, can be misaligned with the φX174 dsDNA. Numbers above the bar graph are the exact number of microhomology tracts of each given length. B, RecA strand exchange assays conducted with either ATP or ATPγS, as indicated. DNA products are labeled as jm (joint molecule), nc (nicked circle), and lds (linear double-stranded DNA). C, quantitation of total strand exchange products (jm + nc) for reactions conducted with either ATP or ATPγS. The error bars represent standard deviation based on three separate experiments. The rates of product formation are obtained by fitting the data with linear functions (black dashed lines).