Molecular Basis of Substrate Recognition of Endonuclease Q from the Euryarchaeon Pyrococcus furiosus.

摘要: ABSTRACT Endonuclease Q (EndoQ), a DNA repair endonuclease, was originally identified in the hyperthermophilic euryarchaeon Pyrococcus furiosus 2015. EndoQ initiates by generating nick on strands containing deaminated bases and an abasic site. Although is thought to be important for maintaining genome integrity certain bacteria archaea, underlying mechanism catalyzed remains unclear. Here, we provide insights into molecular basis of substrate recognition from P. (PfuEndoQ) using biochemical approaches. Our results specificity range kinetic properties PfuEndoQ demonstrate that prefers imide structure nucleobases along with discovery its cleavage activity toward 5,6-dihydrouracil, 5-hydroxyuracil, 5-hydroxycytosine, uridine DNA. The combined binding analyses indicated flips target base duplex, highly dependent spontaneous flipping base. Furthermore, find has relatively relaxed specificity; therefore, role restriction modification systems explored. homolog Bacillus subtilis found not inhibited uracil glycosylase inhibitor B. bacteriophage PBS1, whose completely replaced instead thymine. findings suggest only additional functions but also could act as antiviral enzyme organisms EndoQ. IMPORTANCE (EndoQ) lesion-specific present archaea. To date, it unclear how recognizes damaged bases. Understanding grasp maintenance flipping, enhanced pair instability base, potential digesting viral demonstrated.