6O71

Crystal structure of Csm6 in complex with cdA4 by soaking cdA4 into Csm6

6O71 の概要

• エントリーDOI: 10.2210/pdb6o71/pdb
• 分子名称: Csm6, Cyclic DNA cdA4 (2 entities in total)
• 機能のキーワード: type iii-a crispr-cas system; csm6 in complex with cda4, immune system, immune system-dna complex, immune system/dna
• 由来する生物種: Thermococcus onnurineus; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 102005.97

構造登録者

Jia, N.,Patel, D.J. (登録日: 2019-03-07, 公開日: 2019-07-31, 最終更新日: 2024-03-13)

主引用文献

Jia, N.,Jones, R.,Yang, G.,Ouerfelli, O.,Patel, D.J.
CRISPR-Cas III-A Csm6 CARF Domain Is a Ring Nuclease Triggering Stepwise cA4Cleavage with ApA>p Formation Terminating RNase Activity.
Mol.Cell, 75:944-956.e6, 2019

PubMed Abstract: Type III-A CRISPR-Cas surveillance complexes containing multi-subunit Csm effector, guide, and target RNAs exhibit multiple activities, including formation of cyclic-oligoadenylates (cA) from ATP and subsequent cA-mediated cleavage of single-strand RNA (ssRNA) by the trans-acting Csm6 RNase. Our structure-function studies have focused on Thermococcus onnurineus Csm6 to deduce mechanistic insights into how cA binding to the Csm6 CARF domain triggers the RNase activity of the Csm6 HEPN domain and what factors contribute to regulation of RNA cleavage activity. We demonstrate that the Csm6 CARF domain is a ring nuclease, whereby bound cA is stepwise cleaved initially to ApApApA>p and subsequently to ApA>p in its CARF domain-binding pocket, with such cleavage bursts using a timer mechanism to regulate the RNase activity of the Csm6 HEPN domain. In addition, we establish T. onnurineus Csm6 as an adenosine-specific RNase and identify a histidine in the cA CARF-binding pocket involved in autoinhibitory regulation of RNase activity.

PubMed: 31326273
DOI: 10.1016/j.molcel.2019.06.014

実験手法

X-RAY DIFFRACTION (2.55 Å)