1ktl

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Revision as of 15:48, 12 November 2007

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spinqualitylabelsall models 1ktl, resolution 3.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

The human non-classical major histocompatibility complex molecule HLA-E

Contents 1 Overview 2 Disease 3 About this Structure 4 Reference

Overview

Previous studies of HLA-E allelic polymorphism have indicated that, balancing selection may be acting to maintain two major alleles in most, populations, indicating that a functional difference may exist between the, alleles. The alleles differ at only one amino acid position, where an, arginine at position 107 in HLA-E*0101 (E(R)) is replaced by a glycine in, HLA-E*0103 (E(G)). To investigate possible functional differences, we have, undertaken a study of the physical and biochemical properties of these two, proteins. By comparing expression levels, we found that whereas, steady-state protein levels were similar, the two alleles did in fact, differ with respect to cell surface levels. To help explain this, difference, we undertook studies of the relative differences in peptide, affinity, complex stability, and three-dimensional structure between the, alleles. The crystal structures for HLA-E(G) complexed with two distinct, peptides were determined, and both were compared with the HLA-E(R), structure. No significant differences in the structure of HLA-E were, induced as a result of binding different peptides or by the allelic, substitution at position 107. However, there were clear differences in the, relative affinity for peptide of each heavy chain, which correlated with, and may be explained by differences between their thermal stabilities., These differences were completely consistent with the relative levels of, the HLA-E alleles on the cell surface and may indeed correlate with, functional differences. This in turn may help explain the apparent, balancing selection acting on this locus.

Disease

Known disease associated with this structure: Hypoproteinemia, hypercatabolic OMIM:[109700]

About this Structure

1KTL is a Protein complex structure of sequences from Homo sapiens with SO4 as ligand. Full crystallographic information is available from OCA.

Reference

HLA-E allelic variants. Correlating differential expression, peptide affinities, crystal structures, and thermal stabilities., Strong RK, Holmes MA, Li P, Braun L, Lee N, Geraghty DE, J Biol Chem. 2003 Feb 14;278(7):5082-90. Epub 2002 Oct 30. PMID:12411439

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