Non-canonical binding of the Chaetomium thermophilum PolD4 N-terminal PIP motif to PCNA involves Q-pocket and compact 2-fork plug interactions but no 3₁₀ helix.

ABSTRACT: DNA polymerase δ (Pol δ) is a key enzyme for the maintenance of genome integrity in eukaryotic cells, acting in concert with the sliding clamp processivity factor PCNA (proliferating cell nuclear antigen). Three of the four subunits of human Pol δ interact directly with the PCNA homotrimer via a short, conserved protein sequence known as a PCNA interacting protein (PIP) motif. Here, we describe the identification of a PIP motif located towards the N terminus of the PolD4 subunit of Pol δ (equivalent to human p12) from the thermophilic filamentous fungus Chaetomium thermophilum and present the X-ray crystal structure of the corresponding peptide bound to PCNA at 2.45 Å. Like human p12, the fungal PolD4 PIP motif displays non-canonical binding to PCNA. However, the structures of the human p1

SUBMITTER: Yang D 

PROVIDER: S-EPMC10087552 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature