PDBsum entry 4ill

Hydrolase/RNA

PDB id: 4ill

Contents

Protein chains

278 a.a.

DNA/RNA

Waters ×12

PDB id:

4ill

Name:

Hydrolase/RNA

Title:

Recognition and cleavage of a non-structured crispr RNA by its processing endoribonuclease cas6

Structure:

Crispr-associated endoribonuclease cas6 2. Chain: a, b. Engineered: yes. RNA (5'- r( Gp Cp Up Ap Ap Up Cp Up Ap Cp Up Ap Up Ap Gp Ap Ap Up Up Gp Ap Ap Ap G)-3'). Chain: r, c. Engineered: yes

Source:

Sulfolobus solfataricus. Organism_taxid: 273057. Strain: p2. Gene: cas6b, sso2004. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.48Å R-factor: 0.207 R-free: 0.239

Authors:

Y.Shao,H.Li

Key ref:

Y.Shao and H.Li (2013). Recognition and cleavage of a nonstructured CRISPR RNA by its processing endoribonuclease Cas6. Structure, 21, 385-393. PubMed id: 23454186 DOI: 10.1016/j.str.2013.01.010

Date:

31-Dec-12 Release date: 20-Mar-13

Protein chains

Q97WV8  (CAS6B_SULSO) -  CRISPR-associated endoribonuclease Cas6 2 from Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2)

Seq: 289 a.a.

Struc: 278 a.a.

DNA/RNA chains

A-A-U-C-U-A-C-U-A-U-A-G-A-A-U-G-A-A-G 19 bases

G-C-U-A-A-U-C-U-A-C-U-A-U-A-G-A-A 17 bases

Enzyme reactions

• Enzyme class: E.C.3.1.-.-

DOI no: 10.1016/j.str.2013.01.010

Structure 21:385-393 (2013)

PubMed id: 23454186

Recognition and cleavage of a nonstructured CRISPR RNA by its processing endoribonuclease Cas6.

Y.Shao, H.Li.

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.