7XC7

Cryo-EM structure of a bacterial protein complex

Summary for 7XC7

• Entry DOI: 10.2210/pdb7xc7/pdb
• Related: 7X7A 7X7R 7X8A
• EMDB information: 33040 33046 33056 33114
• Descriptor: CHAT domain protein, RNA (33-MER), RNA (46-mer), ... (5 entities in total)
• Functional Keywords: complex, rna-binding, rna binding protein, rna binding protein-rna complex, rna binding protein/rna
• Biological source: Candidatus Scalindua brodae; More
• Total number of polymer chains: 4
• Total formula weight: 305864.49

Authors

Yu, G.,Wang, X.,Deng, Z.,Zhang, H. (deposition date: 2022-03-23, release date: 2022-11-16, Last modification date: 2024-06-26)

Primary citation

Yu, G.,Wang, X.,Zhang, Y.,An, Q.,Wen, Y.,Li, X.,Yin, H.,Deng, Z.,Zhang, H.
Structure and function of a bacterial type III-E CRISPR-Cas7-11 complex.
Nat Microbiol, 7:2078-2088, 2022

PubMed Abstract: The type III-E CRISPR-Cas system uses a single multidomain effector called Cas7-11 (also named gRAMP) to cleave RNA and associate with a caspase-like protease Csx29, showing promising potential for RNA-targeting applications. The structural and molecular mechanisms of the type III-E CRISPR-Cas system remain poorly understood. Here we report four cryo-electron microscopy structures of Cas7-11 at different functional states. Cas7-11 has four Cas7-like domains, which assemble into a helical filament to accommodate CRISPR RNA (crRNA), and a Cas11-like domain facilitating crRNA-target RNA duplex formation. The Cas7.1 domain is critical for crRNA maturation, whereas Cas7.2 and Cas7.3 are responsible for target RNA cleavage. Target RNA binding induces the structural arrangements of Csx29, potentially exposing the catalytic site of Csx29. These results delineate the molecular mechanisms underlying pre-crRNA processing, target RNA recognition and cleavage for Cas7-11, and provide a structural framework to understand the role of Csx29 in type III-E CRISPR system.

PubMed: 36302881
DOI: 10.1038/s41564-022-01256-z

Experimental method

ELECTRON MICROSCOPY (3.1 Å)