DNA ligase and PCNA: Double-ring down to seal a break in DNA.

ABSTRACT

In this issue of Structure, Sverzhinsky et al. (2022) report structures of archaeal DNA ligase bound to the proliferating cell nuclear antigen (PCNA) sliding clamp and a nicked DNA substrate. The structures provide snapshots of ligation intermediates, which reveal a dynamic nature of the complex and explain how PCNA stimulates the DNA ligase activity.