F pocket flexibility influences the tapasin dependence of two differentially disease-associated MHC Class I proteins

Esam T. Abualrous, Susanne Fritzsche, Zeynep Hein, Mohammed S. Al-Balushi, Peter Reinink, Louise H. Boyle, Ursula Wellbrock, Antony N. Antoniou, Sebastian Springer

Research output: Contribution to journalArticle

27 Citations (Scopus)


The human MHC class I protein HLA-B*27:05 is statistically associated with ankylosing spondylitis, unlike HLA-B*27:09, which differs in a single amino acid in the F pocket of the peptide-binding groove. To understand how this unique amino acid difference leads to a different behavior of the proteins in the cell, we have investigated the conformational stability of both proteins using a combination of in silico and experimental approaches. Here, we show that the binding site of B*27:05 is conformationally disordered in the absence of peptide due to a charge repulsion at the bottom of the F pocket. In agreement with this, B*27:05 requires the chaperone protein tapasin to a greater extent than the conformationally stable B*27:09 in order to remain structured and to bind peptide. Taken together, our data demonstrate a method to predict tapasin dependence and physiological behavior from the sequence and crystal structure of a particular class I allotype.

Original languageEnglish
Pages (from-to)1248-1257
Number of pages10
JournalEuropean Journal of Immunology
Issue number4
Publication statusPublished - Apr 1 2015



  • Ankylosing spondylitis
  • HLA-B27
  • Major histocompatibility complex
  • Molecular dynamics
  • Natively unstructured proteins
  • Protein folding
  • Simulations

ASJC Scopus subject areas

  • Immunology
  • Immunology and Allergy
  • Medicine(all)

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