1b0r
CRYSTAL STRUCTURE OF HLA-A*0201 COMPLEXED WITH A PEPTIDE WITH THE CARBOXYL-TERMINAL GROUP SUBSTITUTED BY A METHYL GROUP
OverviewOverview
The crystal structures of class I major histocompatibility complex (MHC) molecules complexed with antigenic peptides revealed a network of hydrogen bonds between the charged amino- and carboxyl-termini of the peptides and conserved MHC residues at both ends of the peptide binding site. These interactions were shown to contribute substantially to the stability of class I MHC/peptide complexes by thermal denaturation studies using synthetic peptides in which either the amino- or carboxyl-terminal group is substituted by a methyl group. Here we report crystal structures of HLA-A*0201 complexed with these terminally modified synthetic peptides showing that they adopt the same bound conformation as antigenic peptides. A number of variations in peptide conformation were observed for the terminally modified peptides, including in one case, a large conformational difference in four central peptide residues that is apparently caused by the lattice contact. This is reminiscent of the way binding a T-cell receptor changed the conformation of central residues of an MHC-bound peptide. The structures determined identify which conserved hydrogen bonds are eliminated in terminally substituted peptides and suggest an increased energetic importance of the interactions at the peptide termini for MHC-peptide stability.
About this StructureAbout this Structure
1B0R is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of HLA-A*0201 complexed with antigenic peptides with either the amino- or carboxyl-terminal group substituted by a methyl group., Bouvier M, Guo HC, Smith KJ, Wiley DC, Proteins. 1998 Oct 1;33(1):97-106. PMID:9741848 Page seeded by OCA on Fri May 2 10:55:48 2008