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spinqualitylabelsall models 1e27, resolution 2.2Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

NONSTANDARD PEPTIDE BINDING OF HLA-B*5101 COMPLEXED WITH HIV IMMUNODOMINANT EPITOPE KM1(LPPVVAKEI)

Overview

The crystal structures of the human MHC class I allele HLA-B*5101 in, complex with 8-mer, TAFTIPSI, and 9-mer, LPPVVAKEI, immunodominant peptide, epitopes from HIV-1 have been determined by x-ray crystallography. In both, complexes, the hydrogen-bonding network in the N-terminal anchor (P1), pocket is rearranged as a result of the replacement of the standard, tyrosine with histidine at position 171. This results in a nonstandard, positioning of the peptide N terminus, which is recognized by, B*5101-restricted T cell clones. Unexpectedly, the P5 peptide residues, appear to act as anchors, drawing the peptides unusually deeply into the, peptide-binding groove of B51. The unique characteristics of P1 and P5 are, likely to be responsible for the zig-zag conformation of the 9-mer peptide, and the slow assembly of B*5101. A comparison of the surface, characteristics in the alpha1-helix C-terminal region for B51 and other, MHC class I alleles highlights mainly electrostatic differences that may, be important in determining the specificity of human killer cell Ig-like, receptor binding.

About this Structure

1E27 is a Protein complex structure of sequences from Homo sapiens and Human immunodeficiency virus 1. Full crystallographic information is available from OCA.

Reference

Nonstandard peptide binding revealed by crystal structures of HLA-B*5101 complexed with HIV immunodominant epitopes., Maenaka K, Maenaka T, Tomiyama H, Takiguchi M, Stuart DI, Jones EY, J Immunol. 2000 Sep 15;165(6):3260-7. PMID:10975842

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