7N5I

PCNA from Thermococcus gammatolerans: crystal I, collection 1, 1.95 A, 5.22 MGy

7N5I の概要

• エントリーDOI: 10.2210/pdb7n5i/pdb
• 分子名称: DNA polymerase sliding clamp, GLYCEROL, SULFATE ION, ... (4 entities in total)
• 機能のキーワード: pcna, sliding clamp, radioresistance, radiation damage, ionizing radiation, dna binding protein
• 由来する生物種: Thermococcus gammatolerans (strain DSM 15229 / JCM 11827 / EJ3)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 124152.91

構造登録者

Marin-Tovar, Y.,Rudino-Pinera, E. (登録日: 2021-06-05, 公開日: 2022-05-04, 最終更新日: 2023-10-18)

主引用文献

Marin-Tovar, Y.,Serrano-Posada, H.,Diaz-Vilchis, A.,Rudino-Pinera, E.
PCNA from Thermococcus gammatolerans: A protein involved in chromosomal DNA metabolism intrinsically resistant at high levels of ionizing radiation.
Proteins, 90:1684-1698, 2022

PubMed Abstract: Proliferating cell nuclear antigen (PCNA) is an essential protein for cell viability in archaea and eukarya, since it is involved in DNA replication and repair. In order to obtain insights regarding the characteristics that confer radioresistance, the structural study of the PCNA from Thermococcus gammatolerans (PCNA ) in a gradient of ionizing radiation by X-ray crystallography was carried out, together with a bioinformatic analysis of homotrimeric PCNA structures, their sequences, and their molecular interactions. The results obtained from the datasets and the accumulated radiation dose for the last collection from three crystals revealed moderate and localized damage, since even with the loss of resolution, the electron density map corresponding to the last collection allowed to build the whole structure. Attempting to understand this behavior, multiple sequence alignments, and structural superpositions were performed, revealing that PCNA is a protein with a poorly conserved sequence, but with a highly conserved structure. The PCNA presented the highest percentage of charged residues, mostly negatively charged, with a proportion of glutamate more than double aspartate, lack of cysteines and tryptophan, besides a high number of salt bridges. The structural study by X-ray crystallography reveals that the PCNA has the intrinsic ability to resist high levels of ionizing radiation, and the bioinformatic analysis suggests that molecular evolution selected a particular composition of amino acid residues, and their consequent network of synergistic interactions for extreme conditions, as a collateral effect, conferring radioresistance to a protein involved in the chromosomal DNA metabolism of a radioresistant microorganism.

PubMed: 35435259
DOI: 10.1002/prot.26346

実験手法

X-RAY DIFFRACTION (1.95 Å)