7ei1

From Proteopedia

Structure of Pyrococcus furiosus Cas1Cas2 complex

Structural highlights

7ei1 is a 24 chain structure with sequence from Pyrococcus furiosus COM1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 3.9Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

I6TWX9_9EURY 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 spacers, sequences complementary to antecedent mobile elements, and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA). Acts as a dsDNA endonuclease. Involved in the integration of spacer DNA into the CRISPR cassette.[HAMAP-Rule:MF_01470]

Publication Abstract from PubMed

In the adaptation stage of CRISPR-Cas systems, the Cas1-Cas2 integrase captures and integrates new invader-derived spacers into the CRISPR locus, serving as a molecular memory of prior infection. As of yet, the structural information of Cas1-Cas2 complex is available only for two species. Here we present the crystal structure of Cas1-Cas2 complex of Pyrococcus furiosus, which showed a distinct architecture from the known Cas1-Cas2 complexes. The shorter C-terminal tail of Pfu Cas2 directs the Cas1 dimers go in the opposite direction, resulting in a different prespacer binding mode. Based on our structural and mutagenesis results, we modeled a prespacer with a shorter duplex and longer 3' overhangs to bind Pfu Cas1-Cas2 complex. The prespacer preference was confirmed by EMSA, fluorescence polarization, and in vitro integration assays. This model provides a potential explanation for the longer spacer acquisition observed in P. furiosus when deleting both cas4 genes. Our study highlights the diversity of the CRISPR adaptation module.

A distinct structure of Cas1-Cas2 complex provides insights into the mechanism for the longer spacer acquisition in Pyrococcus furiosus.,Tang D, Li H, Wu C, Jia T, He H, Yao S, Yu Y, Chen Q Int J Biol Macromol. 2021 Jul 31;183:379-386. doi: , 10.1016/j.ijbiomac.2021.04.074. Epub 2021 Apr 14. PMID:33864868^[1]

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

References

↑ Tang D, Li H, Wu C, Jia T, He H, Yao S, Yu Y, Chen Q. A distinct structure of Cas1-Cas2 complex provides insights into the mechanism for the longer spacer acquisition in Pyrococcus furiosus. Int J Biol Macromol. 2021 Jul 31;183:379-386. PMID:33864868 doi:10.1016/j.ijbiomac.2021.04.074