7O1E

Crystal structure of PCNA from Chaetomium thermophilum

7O1E の概要

• エントリーDOI: 10.2210/pdb7o1e/pdb
• 分子名称: Proliferating cell nuclear antigen (2 entities in total)
• 機能のキーワード: pcna, dna clamp, dna replication, pip, homotrimer, replication
• 由来する生物種: Chaetomium thermophilum (strain DSM 1495 / CBS 144.50 / IMI 039719)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28756.60

構造登録者

Alphey, M.A.,MacNeill, S.,Yang, D. (登録日: 2021-03-29, 公開日: 2022-04-13, 最終更新日: 2024-01-31)

主引用文献

Yang, D.,Alphey, M.S.,MacNeill, S.A.
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 3 10 helix.
Febs J., 290:162-175, 2023

PubMed 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 p12 and fungal PolD4 PIP motif peptides are quite distinct, with the fungal PolD4 PIP motif lacking the 3 helical segment that characterises most previously identified PIP motifs. Instead, the fungal PolD4 PIP motif binds PCNA via conserved glutamine that inserts into the Q-pocket on the surface of PCNA and with conserved leucine and phenylalanine sidechains forming a compact 2-fork plug that inserts into the hydrophobic pocket on PCNA. Despite the unusual binding mode of the fungal PolD4, isothermal calorimetry (ITC) measurements show that its affinity for PCNA is similar to that of its human orthologue. These observations add to a growing body of information on how diverse proteins interact with PCNA and highlight how binding modes can vary significantly between orthologous PCNA partner proteins.

PubMed: 35942639
DOI: 10.1111/febs.16590

実験手法

X-RAY DIFFRACTION (2.34 Å)