2VTG

Crystal Structure of Human Iba2, trigonal crystal form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural and Functional Characterization of Human Iba Proteins.

Schulze, J.O.Quedenau, C.Roske, Y.Adam, T.Schuler, H.Behlke, J.Turnbull, A.P.Sievert, V.Scheich, C.Mueller, U.Heinemann, U.Bussow, K.

(2008) FEBS J 275: 4627

  • DOI: 10.1111/j.1742-4658.2008.06605.x
  • Primary Citation of Related Structures:  
    2JJZ, 2VTG

  • PubMed Abstract: 
  • Iba2 is a homolog of ionized calcium-binding adapter molecule 1 (Iba1), a 17-kDa protein that binds and cross-links filamentous actin (F-actin) and localizes to membrane ruffles and phagocytic cups. Here, we present the crystal structure of human Iba2 and its homodimerization properties, F-actin cross-linking activity, cellular localization and recruitment upon bacterial invasion in comparison with Iba1 ...

    Iba2 is a homolog of ionized calcium-binding adapter molecule 1 (Iba1), a 17-kDa protein that binds and cross-links filamentous actin (F-actin) and localizes to membrane ruffles and phagocytic cups. Here, we present the crystal structure of human Iba2 and its homodimerization properties, F-actin cross-linking activity, cellular localization and recruitment upon bacterial invasion in comparison with Iba1. The Iba2 structure comprises two central EF-hand motifs lacking bound Ca2+. Iba2 crystallized as a homodimer stabilized by a disulfide bridge and zinc ions. Analytical ultracentrifugation revealed a different mode of dimerization under reducing conditions that was independent of Ca2+. Furthermore, no binding of Ca2+ up to 0.1 mM was detected by equilibrium dialysis. Correspondingly, Iba EF-hand motifs lack residues essential for strong Ca2+ coordination. Sedimentation experiments and microscopy detected pronounced, indistinguishable F-actin binding and cross-linking activity of Iba1 and Iba2 with induction of F-actin bundles. Fluorescent Iba fusion proteins were expressed in HeLa cells and co-localized with F-actin. Iba1 was recruited into cellular projections to a larger extent than Iba2. Additionally, we studied Iba recruitment in a Shigella invasion model that induces cytoskeletal rearrangements. Both proteins were recruited into the bacterial invasion zone and Iba1 was again concentrated slightly higher in the cellular extensions.


    Organizational Affiliation

    Max Delbrück Center for Molecular Medicine, Berlin, Germany.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
IONIZED CALCIUM-BINDING ADAPTER MOLECULE 2A150Homo sapiensMutation(s): 0 
Gene Names: AIF1LC9orf58IBA2UNQ672/PRO1306
UniProt & NIH Common Fund Data Resources
Find proteins for Q9BQI0 (Homo sapiens)
Explore Q9BQI0 
Go to UniProtKB:  Q9BQI0
PHAROS:  Q9BQI0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9BQI0
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A]
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download Ideal Coordinates CCD File 
D [auth A]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.53α = 90
b = 70.53β = 90
c = 95.19γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-07-14
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance