Saccharomyces cerevisiae RAD51, RAD55, and RAD57 genes, required for genetic recombination and DNA double-strand-break repair, encode proteins homologous to one another and to the Escherichia coli RecA protein. Rad51 protein catalyzes the DNA strand-exchange reaction with a dependence on ATP and on the heterotrimeric single-strand DNA (ssDNA) binding factor replication protein A (RPA). By sever...

Isothermal amplification, such as hybridization chain reaction (HCR), is a simple and reliable method for detecting signal amplification. However, the hairpin in HCR will not fully participate reaction. And after opened, distance between fluorophore quencher does change much. Therefore, magnification limited. Here, we designed new isothermal amplification named assemble nicked displacement (HAN...

Replication forks are halted by many types of DNA damage. At the site of a leading-strand DNA lesion, forks may stall and leave the lesion in a single-strand gap. Fork regression is the first step in several proposed pathways that permit repair without generating a double-strand break. Using model DNA substrates designed to mimic one of the known structures of a fork stalled at a leading-strand...

Under conditions that diminish secondary structure in single-stranded DNA, stable presynaptic filaments can be formed by recA protein in the presence of the nonhydrolyzable analog ATP gamma S, without the need for Escherichia coli single strand binding protein. Such stable presynaptic filaments resemble those formed in the presence of ATP and pair efficiently with homologous duplex DNA. Since t...

The DNA Polymerase III holoenzyme forms initiation complexes on primed DNA in an ATP-dependent reaction. We demonstrate that the nonhydrolyzable ATP analog, ATP gamma S, supports the formation of an isolable leading strand complex that loads and replicates the lagging strand only in the presence of ATP, beta, and the single-stranded DNA binding protein. The single endogenous DnaX complex within...

[Reaction: see text]. The photolysis of CpW(CO)3Me has been shown to produce methyl radicals and to cleave DNA in a single-stranded manner, and preliminary evidence implicated a carbon-centered radical in this process. In this work, the mechanism of strand scission in this reaction was determined to occur by hydrogen atom abstraction from the 4'- and 5'-positions of the deoxyribose moiety of th...