1n2r
From Proteopedia
Revision as of 23:01, 2 May 2008
A natural selected dimorphism in HLA B*44 alters self, peptide reportoire and T cell recognition.
Contents |
Overview
HLA-B*4402 and B*4403 are naturally occurring MHC class I alleles that are both found at a high frequency in all human populations, and yet they only differ by one residue on the alpha2 helix (B*4402 Asp156-->B*4403 Leu156). CTLs discriminate between HLA-B*4402 and B*4403, and these allotypes stimulate strong mutual allogeneic responses reflecting their known barrier to hemopoeitic stem cell transplantation. Although HLA-B*4402 and B*4403 share >95% of their peptide repertoire, B*4403 presents more unique peptides than B*4402, consistent with the stronger T cell alloreactivity observed toward B*4403 compared with B*4402. Crystal structures of B*4402 and B*4403 show how the polymorphism at position 156 is completely buried and yet alters both the peptide and the heavy chain conformation, relaxing ligand selection by B*4403 compared with B*4402. Thus, the polymorphism between HLA-B*4402 and B*4403 modifies both peptide repertoire and T cell recognition, and is reflected in the paradoxically powerful alloreactivity that occurs across this "minimal" mismatch. The findings suggest that these closely related class I genes are maintained in diverse human populations through their differential impact on the selection of peptide ligands and the T cell repertoire.
Disease
Known disease associated with this structure: Hypoproteinemia, hypercatabolic OMIM:[109700]
About this Structure
1N2R is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
A naturally selected dimorphism within the HLA-B44 supertype alters class I structure, peptide repertoire, and T cell recognition., Macdonald WA, Purcell AW, Mifsud NA, Ely LK, Williams DS, Chang L, Gorman JJ, Clements CS, Kjer-Nielsen L, Koelle DM, Burrows SR, Tait BD, Holdsworth R, Brooks AG, Lovrecz GO, Lu L, Rossjohn J, McCluskey J, J Exp Med. 2003 Sep 1;198(5):679-91. Epub 2003 Aug 25. PMID:12939341 Page seeded by OCA on Sat May 3 02:01:10 2008
