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1fg2
From Proteopedia
CRYSTAL STRUCTURE OF THE LCMV PEPTIDIC EPITOPE GP33 IN COMPLEX WITH THE MURINE CLASS I MHC MOLECULE H-2DB
Overview
Viral escape, first characterized for the lymphocytic choriomeningitis virus (LCMV) in a mouse transgenic for the P14 T cell-receptor (TCR), can be due to mutations in T-cell epitopes. We have measured the affinity between the H-2D(b) containing the wild-type and two of its "viral escape" epitopes, as well as other altered peptide ligands (APL), by using BIACORE analysis, and solved the crystal structure of H-2D(b) in complex with the wild-type peptide at 2.75 A resolution. We show that viral escape is due to a 50 to 100-fold reduction in the level of affinity between the P14 TCR and the binary complexes of the MHC molecule with the different peptides. Structurally, one of the mutations alters a TCR contact residue, while the effect of the other on the binding of the TCR must be indirect through structural rearrangements. The former is a null ligand, while the latter still leads to some central tolerance. This work defines the structural and energetic threshold for viral escape.
About this Structure
1FG2 is a Protein complex structure of sequences from Mus musculus. Full crystallographic information is available from OCA.
Reference
Viral escape at the molecular level explained by quantitative T-cell receptor/peptide/MHC interactions and the crystal structure of a peptide/MHC complex., Tissot AC, Ciatto C, Mittl PR, Grutter MG, Pluckthun A, J Mol Biol. 2000 Sep 29;302(4):873-85. PMID:10993729 Page seeded by OCA on Fri May 2 16:16:51 2008
