Defining rules for the peptide-MHC class II interaction.

Recent work has begun to clarify the molecular events governing peptide interaction with MHC class II proteins. The requirements for peptide binding to class I and class II molecules seem to be similar. Despite differences in peptide length, anchor residues defining allele-specific peptide motifs can also be found in class II binding peptides. The presence of conserved and allele-specific anchors appears to explain the promiscuity and the specificity of peptide recognition by DR molecules.