4doz

Crystal structure of Pyrococcus furiosus Cmr2 (Cas10)

spinqualitylabelsall models 4doz, resolution 3.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4doz is a 1 chain structure with sequence from Pyrfu. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ZN Gene: PF1129 (PYRFU) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [CMR2_PYRFU] 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), formerly called psiRNA (prokaryotic silencing) in this organism. Part of the Cmr ribonucleoprotein complex which has divalent cation-dependent endoribonuclease activity specific for ssRNA complementary to the crRNA, generating 5' hydroxy- and 3' phosphate or 2'-3' cyclic phosphate termini. It is not known which subunit has endoribonuclease activity. Cmr complex does not cleave ssDNA complementary to the crRNA. Cleavage of invading RNA is guided by the crRNA; substrate cleavage occurs a fixed distance (14 nt) from the 3' end of the crRNA. In vitro reconstitution shows Cmr1-2 and Cmr5 are not necessary for cleavage. Probably not the subunit that cleaves pre-crRNA, as mutation of numerous metal-binding residues have no effect on cleavage by assembled complex. Publication Abstract from PubMed CRISPR RNAs (crRNAs) mediate sequence-specific silencing of invading viruses and plasmids in prokaryotes. The crRNA-Cmr protein complex cleaves complementary RNA. We report the crystal structure of Pyrococcus furiosus Cmr2 (Cas10), a component of this Cmr complex and the signature protein in type III CRISPR systems. The structure reveals a nucleotide cyclase domain with a set of conserved catalytic residues that associates with an unexpected deviant cyclase domain like dimeric cyclases. Additionally, two helical domains resemble the thumb domain of A-family DNA polymerase and Cmr5, respectively. Our results suggest that Cmr2 possesses novel enzymatic activity that remains to be elucidated. Crystal structure of Cmr2 suggests a nucleotide cyclase-related enzyme in type III CRISPR-Cas systems.,Zhu X, Ye K FEBS Lett. 2012 Mar 23;586(6):939-45. doi: 10.1016/j.febslet.2012.02.036. Epub, 2012 Feb 28. PMID:22449983 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Endonuclease

Proteopedia Page Contributors and Editors (what is this?)

OCA