8U7B

Crystal structure of Apo form of Short Prokaryotic Argonaute TIR-APAZ (SPARTA) heterodimer

8U7B の概要

• エントリーDOI: 10.2210/pdb8u7b/pdb
• 分子名称: TIR domain-containing protein, Piwi domain-containing protein, PROLINE, ... (5 entities in total)
• 機能のキーワード: sparta, short prokaryotic argonaute, tir, apaz, rna binding protein
• 由来する生物種: Thermoflavifilum thermophilum; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 112362.28

構造登録者

Kottur, J.,Aggarwal, A.K. (登録日: 2023-09-15, 公開日: 2024-06-12, 最終更新日: 2024-06-19)

主引用文献

Kottur, J.,Malik, R.,Aggarwal, A.K.
Nucleic acid mediated activation of a short prokaryotic Argonaute immune system.
Nat Commun, 15:4852-4852, 2024

PubMed Abstract: A short prokaryotic Argonaute (pAgo) TIR-APAZ (SPARTA) defense system, activated by invading DNA to unleash its TIR domain for NAD(P) hydrolysis, was recently identified in bacteria. We report the crystal structure of SPARTA heterodimer in the absence of guide-RNA/target-ssDNA (2.66 Å) and a cryo-EM structure of the SPARTA oligomer (tetramer of heterodimers) bound to guide-RNA/target-ssDNA at nominal 3.15-3.35 Å resolution. The crystal structure provides a high-resolution view of SPARTA, revealing the APAZ domain as equivalent to the N, L1, and L2 regions of long pAgos and the MID domain containing a unique insertion (insert57). Cryo-EM structure reveals regions of the PIWI (loop10-9) and APAZ (helix αN) domains that reconfigure for nucleic-acid binding and decrypts regions/residues that reorganize to expose a positively charged pocket for higher-order assembly. The TIR domains amass in a parallel-strands arrangement for catalysis. We visualize SPARTA before and after RNA/ssDNA binding and uncover the basis of its active assembly leading to abortive infection.

PubMed: 38844755
DOI: 10.1038/s41467-024-49271-4

実験手法

X-RAY DIFFRACTION (2.66 Å)