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-Structure paper
Title | Essential structural and functional roles of the Cmr4 subunit in RNA cleavage by the Cmr CRISPR-Cas complex. |
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Journal, issue, pages | Cell Rep, Vol. 9, Issue 5, Page 1610-1617, Year 2014 |
Publish date | Dec 11, 2014 |
Authors | Nancy F Ramia / Michael Spilman / Li Tang / Yaming Shao / Joshua Elmore / Caryn Hale / Alexis Cocozaki / Nilakshee Bhattacharya / Rebecca M Terns / Michael P Terns / Hong Li / Scott M Stagg / |
PubMed Abstract | The Cmr complex is the multisubunit effector complex of the type III-B clustered regularly interspaced short palindromic repeats (CRISPR)-Cas immune system. The Cmr complex recognizes a target RNA ...The Cmr complex is the multisubunit effector complex of the type III-B clustered regularly interspaced short palindromic repeats (CRISPR)-Cas immune system. The Cmr complex recognizes a target RNA through base pairing with the integral CRISPR RNA (crRNA) and cleaves the target at multiple regularly spaced locations within the complementary region. To understand the molecular basis of the function of this complex, we have assembled information from electron microscopic and X-ray crystallographic structural studies and mutagenesis of a complete Pyrococcus furiosus Cmr complex. Our findings reveal that four helically packed Cmr4 subunits, which make up the backbone of the Cmr complex, act as a platform to support crRNA binding and target RNA cleavage. Interestingly, we found a hook-like structural feature associated with Cmr4 that is likely the site of target RNA binding and cleavage. Our results also elucidate analogies in the mechanisms of crRNA and target molecule binding by the distinct Cmr type III-A and Cascade type I-E complexes. |
External links | Cell Rep / PubMed:25482566 / PubMed Central |
Methods | EM (single particle) / EM (helical sym.) / X-ray diffraction |
Resolution | 2.85 - 13.0 Å |
Structure data | EMDB-6165: EMDB-6166: EMDB-6167: PDB-4rdp: |
Source |
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Keywords | RNA BINDING PROTEIN / RRM / Ferredoxin-like fold |