EMD-9656

Single-particle
3.4 Å
EMD-9656 Deposition: 21/09/2018
Map released: 12/12/2018
Last modified: 23/01/2019
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-9656

Type III-A Csm complex, Cryo-EM structure of Csm-NTR, ATP bound

EMD-9656

Single-particle
3.4 Å
EMD-9656 Deposition: 21/09/2018
Map released: 12/12/2018
Last modified: 23/01/2019
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Streptococcus thermophilus ND03
Sample: Csm-NTR complex, ATP bound
Fitted models: 6ifr (Avg. Q-score: 0.456)

Deposition Authors: You L, Ma J, Wang J, Zhang X, Wang Y
Structure Studies of the CRISPR-Csm Complex Reveal Mechanism of Co-transcriptional Interference
You L, Ma J , Wang J, Artamonova D , Wang M, Liu L , Xiang H, Severinov K, Zhang X, Wang Y
(2019) Cell , 176 , 239 - 253.e16
PUBMED: 30503210
DOI: doi:10.1016/j.cell.2018.10.052
ISSN: 1097-4172
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.