6IFY

Type III-A Csm complex, Cryo-EM structure of Csm-CTR1

Summary for 6IFY

• Entry DOI: 10.2210/pdb6ify/pdb
• EMDB information: 9658
• Descriptor: Type III-A CRISPR-associated protein Csm1, Type III-A CRISPR-associated protein Csm2, Type III-A CRISPR-associated RAMP protein Csm3, ... (8 entities in total)
• Functional Keywords: csm complex, type iii-a, crispr-cas system, rna binding protein
• Biological source: Streptococcus thermophilus ND03; More
• Total number of polymer chains: 10
• Total formula weight: 290518.11

Authors

You, L.,Ma, J.,Wang, J.,Zhang, X.,Wang, Y. (deposition date: 2018-09-21, release date: 2018-12-12, Last modification date: 2024-03-27)

Primary citation

You, L.,Ma, J.,Wang, J.,Artamonova, D.,Wang, M.,Liu, L.,Xiang, H.,Severinov, K.,Zhang, X.,Wang, Y.
Structure Studies of the CRISPR-Csm Complex Reveal Mechanism of Co-transcriptional Interference
Cell, 176:239-253.e16, 2019

PubMed Abstract: Csm, a type III-A CRISPR-Cas interference complex, is a CRISPR RNA (crRNA)-guided RNase that also possesses target RNA-dependent DNase and cyclic oligoadenylate (cOA) synthetase activities. However, the structural features allowing target RNA-binding-dependent activation of DNA cleavage and cOA generation remain unknown. Here, we report the structure of Csm in complex with crRNA together with structures of cognate or non-cognate target RNA bound Csm complexes. We show that depending on complementarity with the 5' tag of crRNA, the 3' anti-tag region of target RNA binds at two distinct sites of the Csm complex. Importantly, the interaction between the non-complementary anti-tag region of cognate target RNA and Csm1 induces a conformational change at the Csm1 subunit that allosterically activates DNA cleavage and cOA generation. Together, our structural studies provide crucial insights into the mechanistic processes required for crRNA-meditated sequence-specific RNA cleavage, RNA target-dependent non-specific DNA cleavage, and cOA generation.

PubMed: 30503210
DOI: 10.1016/j.cell.2018.10.052

Experimental method

ELECTRON MICROSCOPY (3.8 Å)