1IAK

HISTOCOMPATIBILITY ANTIGEN I-AK

Summary for 1IAK

• Entry DOI: 10.2210/pdb1iak/pdb
• Descriptor: MHC CLASS II I-AK, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: histocompatibility antigen, mhc, peptide complex, histocompatibility antigen i-ak
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 3
• Total formula weight: 46794.19

Authors

Fremont, D.H.,Unanue, E.R.,Hendrickson, W.A. (deposition date: 1997-11-18, release date: 1998-04-15, Last modification date: 2024-10-23)

Primary citation

Fremont, D.H.,Monnaie, D.,Nelson, C.A.,Hendrickson, W.A.,Unanue, E.R.
Crystal structure of I-Ak in complex with a dominant epitope of lysozyme.
Immunity, 8:305-317, 1998

PubMed Abstract: We have determined the structure of murine MHC class II I-Ak in complex with a naturally processed peptide from hen egg lysozyme (HEL residues 50-62) at 1.9 A resolution. These results provide a structural basis for the I-Ak peptide-binding motif. Binding is established by the deep burial of five anchor side chains into specific pockets of the I-Ak binding groove, with a zen-like fit of an aspartic acid in the P1 pocket. We also show that in the I-Ak alpha chain, a bulge occurs in the first strand of the peptide-binding platform, an insertion probably common to all I-A and HLA-DQ alleles. The I-Ak beta chain has a deletion in the helical region adjacent to the P7 pocket and an insertion in the helical region neighboring the P1 pocket. As a result of these structural features, the extended HEL peptide dips low into the center of the I-Ak groove and reaches toward solvent at its C-terminal end.

PubMed: 9529148
DOI: 10.1016/S1074-7613(00)80536-1

Experimental method

X-RAY DIFFRACTION (1.9 Å)