3PKM: Crystal Structure Of Cas6 With Its Substrate Rna

Citation:
Abstract
The CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats) found in prokaryotic genomes confer small RNA-mediated protection against viruses and other invaders. CRISPR loci contain iterations of a short repeat sequence alternating with small segments of varying invader-derived sequences. Distinct families of CRISPR-associated Cas proteins function to cleave within the repeat sequence of CRISPR transcripts and produce the individual invader-targeting crRNAs. Here, we report the crystal structure of Pyrococcus furiosus Cas6 bound with a repeat RNA at 3.2 A resolution. In contrast to other Cas families of endonucleases, Cas6 clasps nucleotides 2-9 of the repeat RNA using its two ferredoxin-like domains, and the enzyme-anchored 5' end tethers the distal cleavage site of the RNA between nucleotides 22 and 23 to the predicted enzyme active site on the opposite side of the ferrodoxin-like domains. Our findings suggest a wrap-around mechanism for CRISPR RNA recognition and cleavage by Cas6 and related processing endonucleases.
PDB ID: 3PKMDownload
MMDB ID: 89083
PDB Deposition Date: 2010/11/11
Updated in MMDB: 2011/05
Experimental Method:
x-ray diffraction
Resolution: 3.1  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 3PKM: dimeric; determined by author
Molecular Components in 3PKM
Label Count Molecule
Protein (1 molecule)
1
Cas6 Protein(Gene symbol: PF_RS05680)
Molecule annotation
Nucleotide(1 molecule)
1
5'-r(*ap*up*up*ap*cp*ap*ap*up*ap*a)-3'
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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