Allele-specific DNA-protein interactions associated with the X-box regulatory region of the DQB1*0302 gene.

The X box is an essential transcriptional regulatory region for both constitutive and inducible expression of HLA-class II genes, and, while highly conserved among class II genes, both locus- and allele-specific polymorphisms exist. Using gel regardation analysis, we have analyzed the binding of B cell nuclear proteins to the X box regions of the DQB1*0302, 0301, and DRA genes and have identified two distinct X box binding complexes which differ for the diabetes-associated DQB10302 allele.