8D1V

Cryo-EM structure of guide RNA and target RNA bound Cas7-11

Summary for 8D1V

• Entry DOI: 10.2210/pdb8d1v/pdb
• EMDB information: 27138
• Descriptor: CRISPR-associated RAMP family protein, CRISPR RNA (34-MER), SS target RNA (5'-R(P*AP*GP*CP*UP*UP*GP*GP*UP*UP*CP*AP*AP*AP*GP*AP*AP*CP*G)-3'), ... (4 entities in total)
• Functional Keywords: crispr, type iii-e cas7-11, rna binding protein, rna binding protein-rna complex, rna binding protein/rna
• Biological source: Desulfonema ishimotonii; More
• Total number of polymer chains: 3
• Total formula weight: 200828.60

Authors

Rai, J.,Goswami, H.,Li, H. (deposition date: 2022-05-27, release date: 2022-11-02, Last modification date: 2025-05-14)

Primary citation

Goswami, H.N.,Rai, J.,Das, A.,Li, H.
Molecular mechanism of active Cas7-11 in processing CRISPR RNA and interfering target RNA.
Elife, 11:-, 2022

PubMed Abstract: Cas7-11 is a Type III-E CRISPR Cas effector that confers programmable RNA cleavage and has potential applications in RNA interference. Cas7-11 encodes a single polypeptide containing four Cas7- and one Cas11-like segments that obscures the distinction between the multi-subunit Class 1 and the single-subunit Class-2 CRISPR Cas systems. We report a cryo-EM (cryo-electron microscopy) structure of the active Cas7-11 from (DiCas7-11) that reveals the molecular basis for RNA processing and interference activities. DiCas7-11 arranges its Cas7- and Cas11-like domains in an extended form that resembles the backbone made up by four Cas7 and one Cas11 subunits in the multi-subunit enzymes. Unlike the multi-subunit enzymes, however, the backbone of DiCas7-11 contains evolutionarily different Cas7 and Cas11 domains, giving rise to their unique functionality. The first Cas7-like domain nearly engulfs the last 15 direct repeat nucleotides in processing and recognition of the CRISPR RNA, and its free-standing fragment retains most of the activity. Both the second and the third Cas7-like domains mediate target RNA cleavage in a metal-dependent manner. The structure and mutational data indicate that the long variable insertion to the fourth Cas7 domain has little impact on RNA processing or targeting, suggesting the possibility for engineering a compact and programmable RNA interference tool.

PubMed: 36190192
DOI: 10.7554/eLife.81678

Experimental method

ELECTRON MICROSCOPY (2.82 Å)