4ILM

CRISPR RNA Processing endoribonuclease

Summary for 4ILM

• Entry DOI: 10.2210/pdb4ilm/pdb
• Related: 3PKM 4ILL 4ILR
• Descriptor: CRISPR-associated endoribonuclease Cas6 2, RNA (5'-R(*GP*CP*UP*AP*AP*UP*CP*UP*AP*CP*UP*AP*UP*AP*GP*A)-3') (2 entities in total)
• Functional Keywords: rrm, endoribonuclease, rna, hydrolase-rna complex, hydrolase/rna
• Biological source: Sulfolobus solfataricus; More
• Total number of polymer chains: 16
• Total formula weight: 302009.65

Authors

Shao, Y.,Li, H. (deposition date: 2012-12-31, release date: 2013-03-20, Last modification date: 2024-02-28)

Primary citation

Shao, Y.,Li, H.
Recognition and cleavage of a nonstructured CRISPR RNA by its processing endoribonuclease Cas6.
Structure, 21:385-393, 2013

PubMed Abstract: Clustered regularly interspaced short palindromic repeats (CRISPRs) confer adaptive immunity to prokaryotes through a small RNA-mediated mechanism. Specific endoribonucleases are required by all CRISPR-bearing organisms to process CRISPR RNAs into small RNA that serve as guides for defensive effector complexes. The molecular mechanism of how the endoribonucleases process the class of CRISPR RNA containing no predicted secondary structural features remains largely elusive. Here, we report cocrystal structures of a processing endoribonuclease bound with a noncleavable RNA substrate and its product-like fragment derived from a nonpalindramic repeat. The enzyme stabilizes a short RNA stem-loop structure near the cleavage site and cleaves the phosphodiester bond using an active site comprised of arginine and lysine residues. The distinct RNA binding and cleavage mechanisms underline the diversity in CRISPR RNA processing.

PubMed: 23454186
DOI: 10.1016/j.str.2013.01.010

Experimental method

X-RAY DIFFRACTION (3.068 Å)