Biochemical Assessment of the Mutant Sliding ß-Clamp on Stimulation of Endonuclease IV from Staphylococcus aureus.

ABSTRACT

Staphylococcus aureus is a pathogenic bacterium that causes various infections in humans. The emergence of methicillin-resistant Staphylococcus aureus makes treatment more challenging. Recent research has shown that bacterial ß-clamp is not only a processivity factor but can also stimulate the activity of other enzymes of DNA metabolism. This article examines the interaction between apurinic/apyrimidinic (AP) endonuclease IV (Nfo) and ß-clamp from Staphylococcus aureus, which has not been previously researched. Recombinant DNA repair enzymes, beta-clamp, were cloned, expressed, and purified. Biochemical methods were employed to assess the stimulation of beta-clamp-activated AP endonuclease activity of Nfo. We demonstrated that mutations in the C-terminal conserved region led to disruption of stimulation of Nfo AP endonuclease activity. The study provides evidence of a specific interaction between Nfo and ß-clamp, which suggests that ß-clamp may play a more direct role in DNA repair processes than previously thought. These findings have important implications for understanding the mechanism of DNA repair, particularly in relation to the role of ß-clamp. Understanding the underlying mechanisms of interaction between DNA metabolism enzymes can aid in predicting new drug targets for antibiotic resistance battle. Supplementary Information The online version contains supplementary material available at 10.1007/s12088-023-01148-8.