6U9S

Crystal structure of human CD81 large extracellular loop in complex with 5A6 Fab


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.217 

wwPDB Validation   3D Report Full Report

Currently 6U9S does not have a validation slider image.


This is version 1.1 of the entry. See complete history


Literature

A dynamic interaction between CD19 and the tetraspanin CD81 controls B cell co-receptor trafficking.

Susa, K.J.Seegar, T.C.Blacklow, S.C.Kruse, A.C.

(2020) Elife 9

  • DOI: https://doi.org/10.7554/eLife.52337
  • Primary Citation of Related Structures:  
    6U9S

  • PubMed Abstract: 

    CD81 and its binding partner CD19 are core subunits of the B cell co-receptor complex. While CD19 belongs to the extensively studied Ig superfamily, CD81 belongs to a poorly understood family of four-pass transmembrane proteins called tetraspanins. Tetraspanins play important physiological roles by controlling protein trafficking and other processes. Here, we show that CD81 relies on its ectodomain to traffic CD19 to the cell surface. Moreover, the anti-CD81 antibody 5A6, which binds selectively to activated B cells, recognizes a conformational epitope on CD81 that is masked when CD81 is bound to CD19. Mutations of CD81 in this interface suppress its CD19 export activity. These data indicate that the CD81 - CD19 interaction is dynamically regulated upon B cell activation and this dynamism can be exploited to regulate B cell function. These results are not only valuable for understanding B cell biology, but also have important implications for understanding tetraspanin function generally.


  • Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
5A6 FAB Heavy Chain
A, D
232Mus musculusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
5A6 FAB Light Chain
B, E
219Mus musculusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
CD81 antigen
C, F
98Homo sapiensMutation(s): 0 
Gene Names: CD81TAPA1TSPAN28
UniProt & NIH Common Fund Data Resources
Find proteins for P60033 (Homo sapiens)
Explore P60033 
Go to UniProtKB:  P60033
GTEx:  ENSG00000110651 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP60033
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.217 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 40.003α = 90
b = 96.858β = 90
c = 297.091γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHENIXphasing

Structure Validation

View Full Validation Report

Currently 6U9S does not have a validation slider image.



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesR35 CA220340
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)United StatesF31 HL147459

Revision History  (Full details and data files)

  • Version 1.0: 2020-05-13
    Type: Initial release
  • Version 1.1: 2023-10-11
    Changes: Data collection, Database references, Refinement description