5TUP

X-ray Crystal Structure of the Aspergillus fumigatus Sliding Clamp

5TUP の概要

• エントリーDOI: 10.2210/pdb5tup/pdb
• 分子名称: Proliferating cell nuclear antigen (2 entities in total)
• 機能のキーワード: sliding clamp, dna binding protein
• 由来する生物種: Aspergillus fumigatus Z5
• 細胞内の位置: Nucleus : A0A0J5SJF1
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 85221.82

構造登録者

Bruning, J.B.,Marshall, A.C.,Kroker, A.J.,Wegener, K.L.,Rajapaksha, H. (登録日: 2016-11-06, 公開日: 2017-02-22, 最終更新日: 2023-10-04)

主引用文献

Marshall, A.C.,Kroker, A.J.,Murray, L.A.,Gronthos, K.,Rajapaksha, H.,Wegener, K.L.,Bruning, J.B.
Structure of the sliding clamp from the fungal pathogen Aspergillus fumigatus (AfumPCNA) and interactions with Human p21.
FEBS J., 284:985-1002, 2017

PubMed Abstract: The fungal pathogen Aspergillus fumigatus has been implicated in a drastic increase in life-threatening infections over the past decade. However, compared to other microbial pathogens, little is known about the essential molecular processes of this organism. One such fundamental process is DNA replication. The protein responsible for ensuring processive DNA replication is PCNA (proliferating cell nuclear antigen, also known as the sliding clamp), which clamps the replicative polymerase to DNA. Here we present the first crystal structure of a sliding clamp from a pathogenic fungus (A. fumigatus), at 2.6Å. Surprisingly, the structure bears more similarity to the human sliding clamp than other available fungal sliding clamps. Reflecting this, fluorescence polarization experiments demonstrated that AfumPCNA interacts with the PCNA-interacting protein (PIP-box) motif of human p21 with an affinity (K ) of 3.1 μm. Molecular dynamics simulations were carried out to better understand how AfumPCNA interacts with human p21. These simulations revealed that the PIP-box bound to AfuPCNA forms a secondary structure similar to that observed in the human complex, with a central 3 helix contacting the hydrophobic surface pocket of AfumPCNA as well as a β-strand that forms an antiparallel sheet with the AfumPCNA surface. Differences in the 3 helix interaction with PCNA, attributed to residue Thr131 of AfumPCNA, and a less stable β-strand formation, attributed to residues Gln123 and His125 of AfumPCNA, are likely causes of the over 10-fold lower affinity of the p21 PIP-box for AfumPCNA as compared to hPCNA.

PubMed: 28165677
DOI: 10.1111/febs.14035

実験手法

X-RAY DIFFRACTION (2.602 Å)