4EYY

Crystal Structure of the IcmR-IcmQ complex from Legionella pneumophila


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.217 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

IcmQ in the Type 4b secretion system contains an NAD+ binding domain.

Farelli, J.D.Gumbart, J.C.Akey, I.V.Hempstead, A.Amyot, W.Head, J.F.McKnight, C.J.Isberg, R.R.Akey, C.W.

(2013) Structure 21: 1361-1373

  • DOI: 10.1016/j.str.2013.05.017

  • PubMed Abstract: 
  • A Type 4b secretion system (T4bSS) is required for Legionella growth in alveolar macrophages. IcmQ associates with IcmR, binds to membranes, and has a critical role in the T4bSS. We have now solved a crystal structure of IcmR-IcmQ to further our unde ...

    A Type 4b secretion system (T4bSS) is required for Legionella growth in alveolar macrophages. IcmQ associates with IcmR, binds to membranes, and has a critical role in the T4bSS. We have now solved a crystal structure of IcmR-IcmQ to further our understanding of this complex. This structure revealed an amphipathic four-helix bundle, formed by IcmR and the N-terminal domain of IcmQ, which is linked to a novel C-terminal domain of IcmQ (Qc) by a linker helix. The Qc domain has structural homology with ADP ribosyltransferase domains in certain bacterial toxins and binds NAD(+) with a dissociation constant in the physiological range. Structural homology and molecular dynamics were used to identify an extended NAD(+) binding site on Qc, and the resulting model was tested by mutagenesis and binding assays. Based on the data, we suggest that IcmR-IcmQ binds to membranes, where it may interact with, or perhaps modify, a protein in the T4bSS when NAD(+) is bound.


    Organizational Affiliation

    Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118-2526, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
IcmR
R
120Legionella pneumophila subsp. pneumophila (strain Philadelphia 1 / ATCC 33152 / DSM 7513)Gene Names: icmR
Find proteins for Q5ZYC9 (Legionella pneumophila subsp. pneumophila (strain Philadelphia 1 / ATCC 33152 / DSM 7513))
Go to UniProtKB:  Q5ZYC9
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
IcmQ
Q
191N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.217 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 68.948α = 90.00
b = 113.411β = 90.00
c = 49.465γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
HKL-2000data collection
SHARPphasing
PHENIXrefinement
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-05-22
    Type: Initial release
  • Version 1.1: 2014-07-16
    Type: Database references