7TUG | pdb_00007tug

Crystal structure of Tapasin in complex with PaSta2-Fab

• PDB DOI: https://doi.org/10.2210/pdb7TUG/pdb

• Classification: IMMUNE SYSTEM
• Organism(s): Homo sapiens, Mus musculus
• Expression System: Drosophila melanogaster, Homo sapiens
• Mutation(s): No 


• Deposited: 2022-02-02 Released: 2022-09-07 
• Deposition Author(s): Jiang, J., Natarajan, K., Taylor, D.K., Boyd, L.F., Margulies, D.H.
• Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.90 Å
• R-Value Free: 
  0.332 (Depositor), 0.323 (DCC) 
• R-Value Work: 
  0.282 (Depositor), 0.282 (DCC) 
• R-Value Observed: 
  0.285 (Depositor) 

Starting Model: experimental

Literature

Structural mechanism of tapasin-mediated MHC-I peptide loading in antigen presentation.

Jiang, J., Taylor, D.K., Kim, E.J., Boyd, L.F., Ahmad, J., Mage, M.G., Truong, H.V., Woodward, C.H., Sgourakis, N.G., Cresswell, P., Margulies, D.H., Natarajan, K.

(2022) Nat Commun 13: 5470-5470

• PubMed: 36115831 
• DOI: https://doi.org/10.1038/s41467-022-33153-8
• Primary Citation Related Structures: 
  7TUC, 7TUD, 7TUE, 7TUF, 7TUG, 7TUH


• PubMed Abstract: 
  

  Loading of MHC-I molecules with peptide by the catalytic chaperone tapasin in the peptide loading complex plays a critical role in antigen presentation and immune recognition. Mechanistic insight has been hampered by the lack of detailed structural information concerning tapasin-MHC-I. We present here crystal structures of human tapasin complexed with the MHC-I molecule HLA-B*44:05, and with each of two anti-tapasin antibodies. The tapasin-stabilized peptide-receptive state of HLA-B*44:05 is characterized by distortion of the peptide binding groove and destabilization of the β ₂ -microglobulin interaction, leading to release of peptide. Movements of the membrane proximal Ig-like domains of tapasin, HLA-B*44:05, and β ₂ -microglobulin accompany the transition to a peptide-receptive state. Together this ensemble of crystal structures provides insights into a distinct mechanism of tapasin-mediated peptide exchange.

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Organizational Affiliation: 
• Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892-1892, USA.
Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
Center for Computational and Genomic Medicine and Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
Department of Immunobiology, Yale University School of Medicine, New Haven, CT, 06520-8011, USA.
Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892-1892, USA. [e-mail].
Molecular Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892-1892, USA. [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 3-mer - A1B1C1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 3-mer - A2B1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content 

• Total Structure Weight: 94.03 kDa 
• Atom Count: 5,304 
• Modeled Residue Count: 752 
• Deposited Residue Count: 866 
• Unique protein chains: 3

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Tapasin	A [auth D]	416	Homo sapiens	Mutation(s): 0  Gene Names: TAPBP, NGS17, TAPA
UniProt & NIH Common Fund Data Resources
Find proteins for O15533 (Homo sapiens) Explore O15533  Go to UniProtKB:  O15533
PHAROS:  O15533 GTEx:  ENSG00000231925
Glycosylation
Glycosylation Sites: 1		Go to GlyGen: O15533-1

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
PaSta2 Fab heavy chain	B [auth H]	230	Mus musculus	Mutation(s): 0

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
PaSta2 Fab kappa light chain	C [auth L]	220	Mus musculus	Mutation(s): 0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NAG	D	2-acetamido-2-deoxy-beta-D-glucopyranose C8 H15 N O6 OVRNDRQMDRJTHS-FMDGEEDCSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.90 Å
• R-Value Free:  0.332 (Depositor), 0.323 (DCC) 
• R-Value Work:  0.282 (Depositor), 0.282 (DCC) 
• R-Value Observed: 0.285 (Depositor) 

Space Group: C 2 2 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 101.09	α = 90
b = 168.82	β = 90
c = 108.66	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
XSCALE	data scaling
PHASER	phasing

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2022-09-07 
Deposition Author(s): Jiang, J., Natarajan, K., Taylor, D.K., Boyd, L.F., Margulies, D.H.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)	United States	--

Revision History  

• Version 1.0: 2022-09-07
  Type: Initial release
  
• Version 1.1: 2022-09-28
  Changes: Database references
• Version 1.2: 2023-10-18
  Changes: Data collection, Refinement description
• Version 1.3: 2024-11-13
  Changes: Structure summary