1ddh
From Proteopedia
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MHC CLASS I H-2DD HEAVY CHAIN COMPLEXED WITH BETA-2 MICROGLOBULIN AND AN IMMUNODOMINANT PEPTIDE P18-I10 FROM THE HUMAN IMMUNODEFICIENCY VIRUS ENVELOPE GLYCOPROTEIN 120
Overview
The crystal structure of the mouse major histocompatibility complex (MHC), class I molecule H-2Dd with an immunodominant peptide, designated P18-I10, (RGPGRAFVTI), from human immunodeficiency virus envelope glycoprotein 120, was determined at 3.2 A resolution. A novel orientation of the alpha3, domain of Dd relative to the alpha1/alpha2 domains results in, significantly fewer contacts between alpha3 and beta2-microglobulin, compared with other MHC class I proteins. Four out of ten peptide residues, (P2 Gly, P3 Pro, P5 Arg and P10 Ile) are nearly completely buried in the, Dd binding groove. This is consistent with previous findings that Dd, exploits a four-residue binding motif comprising a glycine at P2, a, proline at P3, a positively charged residue at P5, and a C-terminal, hydrophobic residue at P9 or P10. The side-chain of P5 Arg is directed, toward the floor of the predominantly hydrophobic binding groove where it, forms two salt bridges and one hydrogen bond with Dd residue Asp77. The, selection of glycine at P2 appears to be due to a narrowing of the B, pocket, relative to that of other class I molecules, caused by Arg66 whose, side-chain folds down into the binding cleft. Residue P3 Pro of P18-I10, occupies part of pocket D, which in Dd is partially split by a prominent, hydrophobic ridge in the floor of the binding groove formed by Trp97 and, Trp114. Residues P6 through P9 form a solvent-exposed bulge, with P7 Phe, protruding the most from the binding groove and thereby probably, constituting a major site of interaction with T cell receptors. A, comparison of H-2Dd/P18-I10 with other MHC class I/peptide complexes of, known structure provides insights into the possible basis for the, specificity of the natural killer cell receptor Ly-49A for several related, class I molecules.
About this Structure
1DDH is a Protein complex structure of sequences from Human immunodeficiency virus 1 and Mus musculus. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of H-2Dd complexed with an immunodominant peptide from human immunodeficiency virus envelope glycoprotein 120., Li H, Natarajan K, Malchiodi EL, Margulies DH, Mariuzza RA, J Mol Biol. 1998;283(1):179-91. PMID:9761682
Page seeded by OCA on Thu Nov 8 13:58:24 2007
