8UNH

Cryo-EM structure of T4 Bacteriophage Clamp Loader with Sliding Clamp

8UNH の概要

• エントリーDOI: 10.2210/pdb8unh/pdb
• 関連するPDBエントリー: 8UNF
• EMDBエントリー: 42399 42402
• 分子名称: Sliding-clamp-loader large subunit, Sliding-clamp-loader small subunit, Sliding clamp, ... (5 entities in total)
• 機能のキーワード: autoinhibited, dna-free, catalytically inactive, stable, replication
• 由来する生物種: Tequatrovirus T4; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 240467.49

構造登録者

Huang, Y.,Marcus, K.,Subramanian, S.,Gee, L.C.,Gorday, K.,Ghaffari-Kashani, S.,Luo, X.,Zhang, L.,O'Donnell, M.,Subramanian, S.,Kuriyan, J. (登録日: 2023-10-19, 公開日: 2023-12-13, 最終更新日: 2024-04-03)

主引用文献

Marcus, K.,Huang, Y.,Subramanian, S.,Gee, C.L.,Gorday, K.,Ghaffari-Kashani, S.,Luo, X.R.,Zheng, L.,O'Donnell, M.,Subramaniam, S.,Kuriyan, J.
Autoinhibition of a clamp-loader ATPase revealed by deep mutagenesis and cryo-EM.
Nat.Struct.Mol.Biol., 31:424-435, 2024

PubMed Abstract: Clamp loaders are AAA+ ATPases that facilitate high-speed DNA replication. In eukaryotic and bacteriophage clamp loaders, ATP hydrolysis requires interactions between aspartate residues in one protomer, present in conserved 'DEAD-box' motifs, and arginine residues in adjacent protomers. We show that functional defects resulting from a DEAD-box mutation in the T4 bacteriophage clamp loader can be compensated by widely distributed single mutations in the ATPase domain. Using cryo-EM, we discovered an unsuspected inactive conformation of the clamp loader, in which DNA binding is blocked and the catalytic sites are disassembled. Mutations that restore function map to regions of conformational change upon activation, suggesting that these mutations may increase DNA affinity by altering the energetic balance between inactive and active states. Our results show that there are extensive opportunities for evolution to improve catalytic efficiency when an inactive intermediate is involved.

PubMed: 38177685
DOI: 10.1038/s41594-023-01177-3

実験手法

ELECTRON MICROSCOPY (3.21 Å)