dUTPase modulates mycobacterial homologous recombination and interacts with the AdnAB helicase-nuclease

This study identifies a previously unrecognized interaction between Mycobacterium tuberculosis dUTPase (Dut) and the AdnAB homologous recombination complex. Using a combination of yeast two-hybrid screening, mycobacterial protein fragment complementation, and biochemical analyses with purified proteins, we show that dUTPase physically interacts with the N-terminal region of AdnA and modulates the activity of the AdnAB helicase-nuclease complex. Biochemical assays demonstrate that Dut enhances AdnAB activity on DNA substrates and alters the AdnAB-DNA interaction. Mutational perturbation of Dut, including catalytic inactivation or deletion of a mycobacteria-specific surface loop, reduces its stimulatory effect on AdnAB in vitro and decreases recombination efficiency in mycobacterial cells. Together, these results support a functional connection between dUTPase and the AdnAB DNA-processing machinery and suggest a potential link between nucleotide metabolism and DNA repair pathways.