Crystallization and preliminary X-ray crystallographic studies of HLA-A*1101 complexed with an HIV-1 decapeptide

A major goal of vaccine research for the prevention of AIDS is to determine the immune correlates of protection against HIV-1 infection. In this context, it is of interest to understand how HLA-­A*1101, a significantly more prevalent class I allele in a cohort of highly HIV-1-exposed persistently seronegative individuals, functions in relation to protective immunity to HIV-1. Towards this goal, a soluble recombinant HLA-A*1101 molecule has been expressed and used to assemble a complex with β2-microglobulin and a Nef decapeptide. The HLA-A*1101/β2m/Nef complex was crystallized by the hanging-drop vapor-diffusion method. The crystal formed in the monoclinic space group P2₁, with unit-cell parameters  a = 77.2, b = 88.5, c = 64.8 Å, β = 90.1°, and contains two molecules in the asymmetric unit. A data set to 2.2 Å resolution was collected and structure determination by molecular replacement is currently in progress. Understanding the three-dimensional structure of the HLA-A*1101/β2m/Nef complex may provide insight into the functional role of this class I allele in relation to protective immunity to HIV-1.