8X5D

The cryo-EM structure of the Mycobacterium tuberculosis CRISPR-Csm complex

8X5D の概要

• エントリーDOI: 10.2210/pdb8x5d/pdb
• EMDBエントリー: 38066
• 分子名称: CRISPR system Cms endoribonuclease Csm3, CRISPR system Cms protein Csm5, RNA (47-MER), ... (4 entities in total)
• 機能のキーワード: mycobacteria crispr-csm complexes, rna binding protein
• 由来する生物種: Mycobacterium tuberculosis; 詳細
• タンパク質・核酸の鎖数: 13
• 化学式量合計: 335732.02

構造登録者

Liu, M.X.,Li, Z.K. (登録日: 2023-11-17, 公開日: 2024-03-06, 最終更新日: 2025-07-02)

主引用文献

Zhang, H.,Shi, M.,Ma, X.,Liu, M.,Wang, N.,Lu, Q.,Li, Z.,Zhao, Y.,Zhao, H.,Chen, H.,Zhang, H.,Jiang, T.,Ouyang, S.,Huo, Y.,Bi, L.
Type-III-A structure of mycobacteria CRISPR-Csm complexes involving atypical crRNAs.
Int.J.Biol.Macromol., 260:129331-129331, 2024

PubMed Abstract: Tuberculosis (TB), a leading cause of mortality globally, is a chronic infectious disease caused by Mycobacterium tuberculosis that primarily infiltrates the lung. The mature crRNAs in M. tuberculosis transcribed from the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) locus exhibit an atypical structure featured with 5' and 3' repeat tags at both ends of the intact crRNA, in contrast to typical Type-III-A crRNAs that possess 5' repeat tags and partial crRNA sequences. However, this structural peculiarity particularly concerning the specific binding characteristics of the 3' repeat end within the mature crRNA within the Csm complex, has not been comprehensively elucidated. Here, our Mycobacteria CRISPR-Csm complexes structure represents the largest Csm complex reported to date. It incorporates an atypical Type-III-A CRISPR RNA (crRNA) (46 nt) with 5' 8-nt and 3' 4-nt repeat sequences in the stoichiometry of Mycobacteria Csm12345 The PAM-independent single-stranded RNAs (ssRNAs) are the most suitable substrate for the Csm complex. The 3'-repeat end trimming of mature crRNA was not necessary for its cleavage activity in Type-III-A Csm complex. Our work broadens our understanding of the Type-III-A Csm complex and identifies another mature crRNA processing mechanism in the Type-III-A CRISPR-Cas system based on structural biology.

PubMed: 38218299
DOI: 10.1016/j.ijbiomac.2024.129331

実験手法

ELECTRON MICROSCOPY (3.1 Å)