4p6i

Crystal structure of the Cas1-Cas2 complex from Escherichia coli

spinqualitylabelsall models 4p6i, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4p6i is a 6 chain structure with sequence from Ecoli. The January 2015 RCSB PDB Molecule of the Month feature on Cascade and CRISPR by David Goodsell is 10.2210/rcsb_pdb/mom_2015_1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: ygbF, cas2, b2754, JW5438 (ECOLI), b2755, cas1, JW2725, pstS, ygbT (ECOLI) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [CAS2_ECOLI] 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). Functions as a ssRNA-specific endoribonuclease (By similarity). [CAS1_ECOLI] 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). Cas1 is thought to be involved in CRISPR adaptation, the first stage of CRISPR immunity. Might be involved in the addition/removal of CRISPR spacers. Endonucleolytically cleaves linear ssRNA, ssDNA and short (34 base) dsDNA as well as branched DNA substrates such as Holliday junctions, replication forks and 5'-flap DNA substrates. Genetic interactions suggest Cas1 interacts with components of the RecBC and RuvB DNA repair systems. Publication Abstract from PubMed The initial stage of CRISPR-Cas immunity involves the integration of foreign DNA spacer segments into the host genomic CRISPR locus. The nucleases Cas1 and Cas2 are the only proteins conserved among all CRISPR-Cas systems, yet the molecular functions of these proteins during immunity are unknown. Here we show that Cas1 and Cas2 from Escherichia coli form a stable complex that is essential for spacer acquisition and determine the 2.3-A-resolution crystal structure of the Cas1-Cas2 complex. Mutations that perturb Cas1-Cas2 complex formation disrupt CRISPR DNA recognition and spacer acquisition in vivo. Active site mutants of Cas2, unlike those of Cas1, can still acquire new spacers, thus indicating a nonenzymatic role of Cas2 during immunity. These results reveal the universal roles of Cas1 and Cas2 and suggest a mechanism by which Cas1-Cas2 complexes specify sites of CRISPR spacer integration. Cas1-Cas2 complex formation mediates spacer acquisition during CRISPR-Cas adaptive immunity.,Nunez JK, Kranzusch PJ, Noeske J, Wright AV, Davies CW, Doudna JA Nat Struct Mol Biol. 2014 May 4. doi: 10.1038/nsmb.2820. PMID:24793649 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Endonuclease 3D structures

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