Macromolecule Content

• Total Structure Weight: 4.61 kDa 
• Atom Count: 326 
• Residue Count: 36 
• Unique protein chains: 2

1KUZ

Solution Structure of the Membrane Proximal Regions of alpha-IIb and beta-3 Integrins

• DOI: 10.2210/pdb1KUZ/pdb

• Classification: CELL ADHESION
• Mutation(s): No 


• Deposited: 2002-01-22 Released: 2002-05-08 
• Deposition Author(s): Weljie, A.M., Hwang, P.M., Vogel, H.J.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: structures with acceptable covalent geometry,structures with the least restraint violations,structures with the lowest energy 

Literature

Solution structures of the cytoplasmic tail complex from platelet integrin alpha IIb- and beta 3-subunits.

Weljie, A.M., Hwang, P.M., Vogel, H.J.

(2002) Proc Natl Acad Sci U S A 99: 5878-5883

• PubMed: 11983888 
• DOI: 10.1073/pnas.092515799
• Primary Citation of Related Structures:  
  1KUP, 1KUZ


• PubMed Abstract: 
  

Integrin adhesion receptors constitute a cell-signaling system whereby interactions in the small cytoplasmic domains of the heterodimeric alpha- and beta-subunits provoke major functional alterations in the large extracellular domains. With two-dimensional NMR spectroscopy, we examined two synthetic peptides [alphaIIb((987)MWKVGFFKRNR) and beta3((716)KLLITIHDRKEFAKFEEERARAKWD)] encompassing the membrane-proximal regions of the cytoplasmic domain motifs from the platelet integrin complex alphaIotaIotabbeta3. These membrane-proximal regions contain two conserved motifs, represented by (989)KVGFFKR in the alphaIIb-subunit, and (716)KLLITIHDR in the beta3-subunit. The dimer interaction consists of two adjacent helices with residues V990 and F993 of the alphaIotaIotab-subunit heavily implicated in the dimer interfacial region, as is I719 of beta3. These residues are situated within the conserved motifs of their respective proteins. Further structural analysis of this unique peptide heterodimer suggests that two distinct conformers are present. The major structural difference between the two conformers is a bend in the beta3-peptide between D723 and A728, whereas the helical character in the other regions remains intact. Earlier mutational analysis has shown that a salt bridge between the side chains of alphaIotaIotab(R955) and beta3(D723) is formed. When this ion pair was modeled into both conformers, increased nuclear Overhauser effect violations suggested that the more bent structure was less able to accommodate this interaction. These results provide a molecular level rationalization for previously reported biochemical studies, as well as a basis for an atomic level understanding of the intermolecular interactions that regulate integrin activity.

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Organizational Affiliation: 

Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
integrin alpha-IIb	A	11	N/A	Mutation(s): 0
Find proteins for P08514 (Homo sapiens) Explore P08514  Go to UniProtKB:  P08514
NIH Common Fund Data Resources
PHAROS:  P08514 GTEx:  ENSG00000005961

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
integrin beta-3	B	25	N/A	Mutation(s): 0
Find proteins for P05106 (Homo sapiens) Explore P05106  Go to UniProtKB:  P05106
NIH Common Fund Data Resources
PHAROS:  P05106 GTEx:  ENSG00000259207

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: structures with acceptable covalent geometry,structures with the least restraint violations,structures with the lowest energy 
• OLDERADO: 1KUZ Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2002-01-22 
• Released Date: 2002-05-08 
Deposition Author(s): Weljie, A.M., Hwang, P.M., Vogel, H.J.

Revision History 

• Version 1.0: 2002-05-08
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance