6NJY

Type IV CRISPR associated RNA endonuclease Cas6 - apo form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.76 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.168 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Structural basis of Type IV CRISPR RNA biogenesis by a Cas6 endoribonuclease.

Taylor, H.N.Warner, E.E.Armbrust, M.J.Crowley, V.M.Olsen, K.J.Jackson, R.N.

(2019) RNA Biol 16: 1438-1447

  • DOI: 10.1080/15476286.2019.1634965
  • Primary Citation of Related Structures:  
    6NJY

  • PubMed Abstract: 
  • Prokaryotic CRISPR-Cas adaptive immune systems rely on small non-coding RNAs derived from CRISPR loci to recognize and destroy complementary nucleic acids. However, the mechanism of Type IV CRISPR RNA (crRNA) biogenesis is poorly understood. To dissect the mechanism of Type IV CRISPR RNA biogenesis, we determined the x-ray crystal structure of the putative Type IV CRISPR associated endoribonuclease Cas6 from Mahella australiensis ( Ma Cas6-IV) and characterized its enzymatic activity with RNA cleavage assays ...

    Prokaryotic CRISPR-Cas adaptive immune systems rely on small non-coding RNAs derived from CRISPR loci to recognize and destroy complementary nucleic acids. However, the mechanism of Type IV CRISPR RNA (crRNA) biogenesis is poorly understood. To dissect the mechanism of Type IV CRISPR RNA biogenesis, we determined the x-ray crystal structure of the putative Type IV CRISPR associated endoribonuclease Cas6 from Mahella australiensis ( Ma Cas6-IV) and characterized its enzymatic activity with RNA cleavage assays. We show that Ma Cas6-IV specifically cleaves Type IV crRNA repeats at the 3' side of a predicted stem loop, with a metal-independent, single-turnover mechanism that relies on a histidine and a tyrosine located within the putative endonuclease active site. Structure and sequence alignments with Cas6 orthologs reveal that although Ma Cas6-IV shares little sequence homology with other Cas6 proteins, all share common structural features that bind distinct crRNA repeat sequences. This analysis of Type IV crRNA biogenesis provides a structural and biochemical framework for understanding the similarities and differences of crRNA biogenesis across multi-subunit Class 1 CRISPR immune systems.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, Utah State University , Logan , UT , USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Type IV CRISPR associated Cas6 RNA endonucleaseA, B248Mahella australiensis 50-1 BONMutation(s): 0 
Gene Names: Mahau_2538
UniProt
Find proteins for F3ZXK6 (Mahella australiensis (strain DSM 15567 / CIP 107919 / 50-1 BON))
Explore F3ZXK6 
Go to UniProtKB:  F3ZXK6
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BGC
Query on BGC

Download Ideal Coordinates CCD File 
L [auth A], M [auth A], X [auth B], Y [auth B]beta-D-glucopyranose
C6 H12 O6
WQZGKKKJIJFFOK-VFUOTHLCSA-N
 Ligand Interaction
SO4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth A] , D [auth A] , E [auth A] , F [auth A] , G [auth A] , H [auth A] , I [auth A] , J [auth A] , 
C [auth A],  D [auth A],  E [auth A],  F [auth A],  G [auth A],  H [auth A],  I [auth A],  J [auth A],  K [auth A],  N [auth B],  O [auth B],  P [auth B],  Q [auth B],  R [auth B],  S [auth B],  T [auth B],  U [auth B],  V [auth B],  W [auth B]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.76 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.168 
  • Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.541α = 90
b = 85.541β = 90
c = 142.587γ = 120
Software Package:
Software NamePurpose
HKL-2000data scaling
SOLVEphasing
RESOLVEmodel building
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-07-10
    Type: Initial release
  • Version 1.1: 2019-09-11
    Changes: Data collection, Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary