1XWR

Crystal structure of the coliphage lambda transcription activator protein CII


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.56 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.250 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of {lambda} CII: Implications for recognition of direct-repeat DNA by an unusual tetrameric organization

Datta, A.B.Panjikar, S.Weiss, M.S.Chakrabarti, P.Parrack, P.

(2005) Proc.Natl.Acad.Sci.USA 102: 11242-11247

  • DOI: 10.1073/pnas.0504535102

  • PubMed Abstract: 
  • The temperate coliphage lambda, after infecting its host bacterium Escherichia coli, can develop either along the lytic or the lysogenic pathway. Crucial to the lysis/lysogeny decision is the homotetrameric transcription-activator protein CII (4 x 11 ...

    The temperate coliphage lambda, after infecting its host bacterium Escherichia coli, can develop either along the lytic or the lysogenic pathway. Crucial to the lysis/lysogeny decision is the homotetrameric transcription-activator protein CII (4 x 11 kDa) of the phage that binds to a unique direct-repeat sequence T-T-G-C-N6-T-T-G-C at each of the three phage promoters it activates: p(E), p(I), and p(aQ). Several regions of CII have been identified for its various functions (DNA binding, oligomerization, and susceptibility to host protease), but the crystal structure of the protein long remained elusive. Here, we present the three-dimensional structure of CII at 2.6-angstroms resolution. The CII monomer is comprised of four alpha helices and a disordered C terminus. The first three helices (alpha1-alpha3) form a compact domain, whereas the fourth helix (alpha4) protrudes in different orientations in each subunit. A four-helix bundle, formed by alpha4 from each subunit, holds the tetramer. The quaternary structure can be described as a dimer of dimers, but the tetramer does not exhibit a closed symmetry. This unusual quaternary arrangement allows the placement of the helix-turn-helix motifs of two of the four CII subunits for interaction with successive major grooves of B-DNA, from one face of DNA. This structure provides a simple explanation for how a homotetrameric protein may recognize a direct-repeat DNA sequence rather than the inverted-repeat sequences of most prokaryotic activators.


    Organizational Affiliation

    Department of Biochemistry, Bose Institute, P1/12 CIT Scheme VIIM, Calcutta 700 054, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Regulatory protein CII
A, B, C, D
97Escherichia phage lambdaMutation(s): 0 
Gene Names: cII
Find proteins for P03042 (Escherichia phage lambda)
Go to UniProtKB:  P03042
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IPA
Query on IPA

Download SDF File 
Download CCD File 
B, D
ISOPROPYL ALCOHOL
2-PROPANOL
C3 H8 O
KFZMGEQAYNKOFK-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.56 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.250 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 63.907α = 90.00
b = 106.794β = 90.00
c = 119.784γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
SOLVEphasing
CNSrefinement
SCALEPACKdata scaling
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-06-21
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance