Biological Assembly 1  

 3D View: Structure

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: immunoprecipitation, isothermal titration calorimetry

Macromolecule Content

• Total Structure Weight: 29.81 kDa 
• Atom Count: 2023 
• Residue Count: 253 
• Unique protein chains: 2

6BA6

Solution structure of Rap1b/talin complex

• DOI: 10.2210/pdb6BA6/pdb
• BMRB: 30353

• Classification: CELL ADHESION
• Organism(s): Mus musculus, Homo sapiens
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2017-10-12 Released: 2017-12-06 
• Deposition Author(s): Zhu, L., Yang, J., Qin, J.
• Funding Organization(s): National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 20 
• Selection Criteria: 20 structures for lowest energy 

Literature

Structure of Rap1b bound to talin reveals a pathway for triggering integrin activation.

Zhu, L., Yang, J., Bromberger, T., Holly, A., Lu, F., Liu, H., Sun, K., Klapproth, S., Hirbawi, J., Byzova, T.V., Plow, E.F., Moser, M., Qin, J.

(2017) Nat Commun 8: 1744-1744

• PubMed: 29170462 
• DOI: 10.1038/s41467-017-01822-8
• Primary Citation of Related Structures:  
  6BA6


• PubMed Abstract: 
  

Activation of transmembrane receptor integrin by talin is essential for inducing cell adhesion. However, the pathway that recruits talin to the membrane, which critically controls talin's action, remains elusive. Membrane-anchored mammalian small GTPase Rap1 is known to bind talin-F0 domain but the binding was shown to be weak and thus hardly studied. Here we show structurally that talin-F0 binds to human Rap1b like canonical Rap1 effectors despite little sequence homology, and disruption of the binding strongly impairs integrin activation, cell adhesion, and cell spreading. Furthermore, while being weak in conventional binary binding conditions, the Rap1b/talin interaction becomes strong upon attachment of activated Rap1b to vesicular membranes that mimic the agonist-induced microenvironment. These data identify a crucial Rap1-mediated membrane-targeting mechanism for talin to activate integrin. They further broadly caution the analyses of weak protein-protein interactions that may be pivotal for function but neglected in the absence of specific cellular microenvironments.

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Organizational Affiliation: 

Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA. [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Talin-1	A	93	Mus musculus	Mutation(s): 0  Gene Names: Tln1, Tln
Find proteins for P26039 (Mus musculus) Explore P26039  Go to UniProtKB:  P26039

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Ras-related protein Rap-1b	B	168	Homo sapiens	Mutation(s): 1  Gene Names: RAP1B, OK/SW-cl.11 EC: 3.6.5.2
Find proteins for P61224 (Homo sapiens) Explore P61224  Go to UniProtKB:  P61224
NIH Common Fund Data Resources
PHAROS:  P61224 GTEx:  ENSG00000127314

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 20 
• Selection Criteria: 20 structures for lowest energy 
• OLDERADO: 6BA6 Olderado

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2017-10-12 
• Released Date: 2017-12-06 
Deposition Author(s): Zhu, L., Yang, J., Qin, J.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)	United States	P01HL073311

Revision History 

• Version 1.0: 2017-12-06
  Type: Initial release
  
• Version 1.1: 2019-12-04
  Changes: Author supporting evidence, Data collection