3ZCJ

Crystal structure of Helicobacter pylori T4SS protein CagL in a tetragonal crystal form with a helical RGD-motif (6 Mol per ASU)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.25 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

A Helical Rgd Motif Promoting Cell Adhesion: Crystal Structures of the Helicobacter Pylori Type Iv Secretion System Pilus Protein Cagl

Barden, S.Lange, S.Tegtmeyer, N.Conradi, J.Sewald, N.Backert, S.Niemann, H.H.

(2013) Structure 21: 1931

  • DOI: 10.1016/j.str.2013.08.018
  • Primary Citation of Related Structures:  3ZCI

  • PubMed Abstract: 
  • RGD tripeptide motifs frequently mediate ligand binding to integrins. The type IV secretion system (T4SS) protein CagL of the gastric pathogen Helicobacter pylori also contains an RGD motif. CagL decorates the T4SS pilus and may function as an adhesi ...

    RGD tripeptide motifs frequently mediate ligand binding to integrins. The type IV secretion system (T4SS) protein CagL of the gastric pathogen Helicobacter pylori also contains an RGD motif. CagL decorates the T4SS pilus and may function as an adhesin for host cells. Whether CagL binds integrins via its RGD motif is under debate. Here, we present crystal structures of CagL revealing an elongated four-helix bundle that appears evolutionarily unrelated to the proposed VirB5 orthologs. The RGD motif is surface-exposed but located within a long α helix. This is unprecedented as previously characterized integrin-binding RGD motifs are located within extended or flexible loops. Yet, adhesion of gastric epithelial cells to CagL was strictly RGD-dependent. Comparison of seven crystallographically independent molecules reveals substantial structural flexibility. Intramolecular disulfide bonds engineered to reduce CagL flexibility resulted in more stable protein, but unable to support cell adhesion. CagL may thus partly unfold during receptor binding.


    Organizational Affiliation

    Structural Biochemistry, Department of Chemistry, Bielefeld University, 33501 Bielefeld, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CAGL
A, B, C, D, E, F
220Helicobacter pylori (strain ATCC 700392 / 26695)N/A
Find proteins for O25272 (Helicobacter pylori (strain ATCC 700392 / 26695))
Go to UniProtKB:  O25272
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
D
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
PO4
Query on PO4

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Download CCD File 
B, F
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A, B, C, D, E, F
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
PEG
Query on PEG

Download SDF File 
Download CCD File 
A
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MLY
Query on MLY
A, B, C, D, E, F
L-PEPTIDE LINKINGC8 H18 N2 O2LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.25 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.205 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 197.122α = 90.00
b = 197.122β = 90.00
c = 106.808γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
PHASERphasing
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-10-09
    Type: Initial release
  • Version 1.1: 2013-11-27
    Type: Database references