Answer:
Amino acids in the alpha helices that interact with the antigens
Step-by-step explanation:
The major histocompatibility complex (MHC) locus contains genes that encode proteins localized in the cell surface which play roles related to the interaction between host and antigen. The MHC locus encodes proteins that are localized on the surface of T cells and bind peptides derived from pathogens, this represents an initial phase of recognition and activates the immune system