The stimulatory effect of CaCl₂, NaCl and NH₄NO₃salts on the ssDNA-binding activity of RecA depends on nucleotide cofactor and buffer pH

Abstract

The single-stranded DNA binding activity of the Escherichia coli RecA protein is crucial for homologous recombination to occur. This and other biochemical activities of ssDNA binding proteins may be affected by various factors. In this study, we analyzed the effect of CaCl2, NaCl and NH4NO3 salts in combination with the pH and nucleotide cofactor effect on the ssDNA-binding activity of RecA. The studies revealed that, in addition to the inhibitory effect, these salts exert also a stimulatory effect on RecA. These effects occur only under very strict conditions, and the presence or absence and the type of nucleotide cofactor play here a major role. It was observed that in contrast to ATP, ATPγS prevented the inhibitory effect of NaCl and NH4NO3, even at very high salt concentration.

DNA-modulated photo-transformation of AgCl to silver nanoparticles: visiting the formation mechanism

“…Numerous studies have demonstrated that high-concentration salt can modulate the interaction, charge and conformation of DNA in polar solvents [67,68]. For example, not only charge screening but also inhibitory effect on ssDNA binding activity have been observed under high ionic strength condition [67,68].…”

“…For example, not only charge screening but also inhibitory effect on ssDNA binding activity have been observed under high ionic strength condition [67,68]. It is therefore possible to control the nanostructure photoconverted from AgCl in the presence of DNA through choice of salt condition.…”

Comparative genomics reveals adaptations of a halotolerant thaumarchaeon in the interfaces of brine pools in the Red Sea

“…There is also a large fraction of genes in the unique genome of RSA3 (12%) encoding for 'repair, replication and recombination' enzymes (for example, methylases and recombinases; Supplementary Table 7), presumably as a consequence of the destabilization effect of salts on biomolecules like DNA and proteins (Ziemienowicz et al, 2011), which also increases homologous recombination events in some microorganisms (Boyandin et al, 2000), preferentially in (halophilic) Archaea than in bacteria (Naor et al, 2012).…”