4XQK

ATP-dependent Type ISP restriction-modification enzyme LlaBIII bound to DNA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.218 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Translocation-coupled DNA cleavage by the Type ISP restriction-modification enzymes

Chand, M.K.Nirwan, N.Diffin, F.M.Aelst, K.V.Kulkarni, M.Pernstich, C.Szczelkun, M.D.Saikrishnan, K.

(2015) Nat.Chem.Biol. 11: 870-877

  • DOI: 10.1038/nchembio.1926

  • PubMed Abstract: 
  • Production of endonucleolytic double-strand DNA breaks requires separate strand cleavage events. Although catalytic mechanisms for simple, dimeric endonucleases are known, there are many complex nuclease machines that are poorly understood. Here we s ...

    Production of endonucleolytic double-strand DNA breaks requires separate strand cleavage events. Although catalytic mechanisms for simple, dimeric endonucleases are known, there are many complex nuclease machines that are poorly understood. Here we studied the single polypeptide Type ISP restriction-modification (RM) enzymes, which cleave random DNA between distant target sites when two enzymes collide after convergent ATP-driven translocation. We report the 2.7-Å resolution X-ray crystal structure of a Type ISP enzyme-DNA complex, revealing that both the helicase-like ATPase and nuclease are located upstream of the direction of translocation, an observation inconsistent with simple nuclease-domain dimerization. Using single-molecule and biochemical techniques, we demonstrate that each ATPase remodels its DNA-protein complex and translocates along DNA without looping it, leading to a collision complex in which the nuclease domains are distal. Sequencing of the products of single cleavage events suggests a previously undescribed endonuclease model, where multiple, stochastic strand-nicking events combine to produce DNA scission.


    Organizational Affiliation

    Division of Biology, Indian Institute of Science Education and Research, Pune, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
LlaBIII
A, B
1578Lactococcus lactis subsp. cremorisMutation(s): 0 
Find proteins for A0A0M3KL05 (Lactococcus lactis subsp. cremoris)
Go to UniProtKB:  A0A0M3KL05
Entity ID: 2
MoleculeChainsLengthOrganism
DNA (28-MER)C,E28unidentified
Entity ID: 3
MoleculeChainsLengthOrganism
DNA (28-MER)D,F28unidentified
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A, B
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.218 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 62.880α = 103.30
b = 112.660β = 90.88
c = 146.210γ = 105.79
Software Package:
Software NamePurpose
PHASERphasing
XDSdata reduction
XSCALEdata scaling
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Wellcome Trust-DBT India AllianceIndia500048-Z-09-Z

Revision History 

  • Version 1.0: 2015-09-16
    Type: Initial release
  • Version 1.1: 2015-09-23
    Type: Data collection
  • Version 1.2: 2015-11-04
    Type: Database references