4K8O

CRYSTAL STRUCTURE OF THE ATPASE DOMAIN OF TAP1 WITH ATP (D645N, D651A MUTANT)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.248 
  • R-Value Observed: 0.250 

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This is version 1.1 of the entry. See complete history


Literature

Mechanistic determinants of the directionality and energetics of active export by a heterodimeric ABC transporter.

Grossmann, N.Vakkasoglu, A.S.Hulpke, S.Abele, R.Gaudet, R.Tampe, R.

(2014) Nat Commun 5: 5419-5419

  • DOI: https://doi.org/10.1038/ncomms6419
  • Primary Citation of Related Structures:  
    4K8O

  • PubMed Abstract: 

    The ATP-binding cassette (ABC) transporter associated with antigen processing (TAP) participates in immune surveillance by moving proteasomal products into the endoplasmic reticulum (ER) lumen for major histocompatibility complex class I loading and cell surface presentation to cytotoxic T cells. Here we delineate the mechanistic basis for antigen translocation. Notably, TAP works as a molecular diode, translocating peptide substrates against the gradient in a strict unidirectional way. We reveal the importance of the D-loop at the dimer interface of the two nucleotide-binding domains (NBDs) in coupling substrate translocation with ATP hydrolysis and defining transport vectoriality. Substitution of the conserved aspartate, which coordinates the ATP-binding site, decreases NBD dimerization affinity and turns the unidirectional primary active pump into a passive bidirectional nucleotide-gated facilitator. Thus, ATP hydrolysis is not required for translocation per se, but is essential for both active and unidirectional transport. Our data provide detailed mechanistic insight into how heterodimeric ABC exporters operate.


  • Organizational Affiliation

    Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Max-von-Laue-Street 9, D-60438 Frankfurt/M., Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Antigen peptide transporter 1271Rattus norvegicusMutation(s): 2 
Gene Names: Abcb2Mtp1Tap1Tap1 Abcb2 Mtp1
UniProt
Find proteins for P36370 (Rattus norvegicus)
Explore P36370 
Go to UniProtKB:  P36370
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP36370
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.248 
  • R-Value Observed: 0.250 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.26α = 90
b = 123.98β = 90
c = 79.91γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
PHASERphasing
PHENIXrefinement
XDSdata reduction
XDSdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-09-03
    Type: Initial release
  • Version 1.1: 2014-12-03
    Changes: Database references