Translesion synthesis(TLS) is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. TLS requires both inserter polymerase for damage bypass and extender polymerase for further synthesis. Recent research shows that Rev1 acts as a regulator and defines mechanism for TLS when compared with PCNA. C-terminus of Rev1 with TLS polymerases κ, η, ι, ξ(Rev3 and Rev7) is reported to be required for the DNA damage tolerance. It is important to understand the molecular basis of the c-terminus of Rev1 and its related interactions with TLS polymerases.
We characterized the complex structure of hRev1-PID(Polymerase-interacting domain) by NMR spectroscopy to understand how Rev1 recruits the TLS polymerases. Furtherly we elucidated the complex structure between hRev1-PID and Pol ξ (Rev7 1-211 and Rev3 846-898) using crystallography at 1.9 A° resolution to explain more about the recruitment manner of Rev1 with Pol ξ. We found that Rev1 directly interacts with Pol κ and Pol ξ simultaneously forming a multi-polymerase inserter/extender complex. Our results suggest that hRev1-PID functions as a ‘hub’, utilizing two preformed docking sites to recognize two different RIMs presented by inserter(polymerase κ, η, ι) and extender(polymerase ξ) translesion polymerases. Our structural studies on human Rev1 polymerase-interacting domain revealed the structural insights into the regulation of human Rev1 for TLS polymerases.