2y8w

From Proteopedia

Structure of CRISPR endoribonuclease Cse3 bound to 20 nt RNA

Structural highlights

2y8w is a 2 chain structure with sequence from Thermus thermophilus HB8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.8Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CAS6_THET8 CRISPR (clustered regularly interspaced short palindromic repeat), is an adaptive immune system that provides protection against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain sequences complementary to antecedent mobile elements and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA). This enzyme processes pre-crRNA into individual crRNA units, but may not actually undergo enzyme turnover, retaining the crRNA product (PubMed:21572442). Generates a 2',3'-cyclic phosphodiester.^[1] ^[2]

Publication Abstract from PubMed

Clustered regularly interspaced short palindromic repeat (CRISPR) chromosomal loci found in prokaryotes provide an adaptive immune system against bacteriophages and plasmids. CRISPR-specific endoRNases produce short RNA molecules (crRNAs) from CRISPR transcripts, which harbor sequences complementary to invasive nucleic acid elements and ensure their selective targeting by CRISPR-associated (Cas) proteins. The extreme sequence divergence of CRISPR-specific endoRNases and their RNA substrates has obscured homology-based comparison of RNA recognition and cleavage mechanisms. Here, we show that Cse3 type CRISPR-specific endoRNases bind a hairpin structure and residues downstream of the cleavage site within the repetitive segment of cognate CRISPR RNA. Cocrystal structures of Cse3-RNA complexes reveal an RNA-induced conformational change in the enzyme active site that aligns the RNA strand for site-specific cleavage. These studies provide insight into a catalytically essential RNA recognition mechanism by a large class of CRISPR-related endoRNases.

An RNA-induced conformational change required for CRISPR RNA cleavage by the endoribonuclease Cse3.,Sashital DG, Jinek M, Doudna JA Nat Struct Mol Biol. 2011 Jun;18(6):680-7. Epub 2011 May 15. PMID:21572442^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Sashital DG, Jinek M, Doudna JA. An RNA-induced conformational change required for CRISPR RNA cleavage by the endoribonuclease Cse3. Nat Struct Mol Biol. 2011 Jun;18(6):680-7. Epub 2011 May 15. PMID:21572442 doi:10.1038/nsmb.2043
↑ Gesner EM, Schellenberg MJ, Garside EL, George MM, Macmillan AM. Recognition and maturation of effector RNAs in a CRISPR interference pathway. Nat Struct Mol Biol. 2011 May 15. PMID:21572444 doi:10.1038/nsmb.2042
↑ Sashital DG, Jinek M, Doudna JA. An RNA-induced conformational change required for CRISPR RNA cleavage by the endoribonuclease Cse3. Nat Struct Mol Biol. 2011 Jun;18(6):680-7. Epub 2011 May 15. PMID:21572442 doi:10.1038/nsmb.2043