Structure/Function Studies of the Androgen Receptor DNA-Binding Region

The onset and progress of prostate cancer is related to the function of the androgen receptor AR, and much of current drug therapy is directed against this protein. AR contains two binding sites a ligand binding domain LBD and a DNA binding domain DBD through which AR regulates gene expression. The proposal focuses on the AR DBD and its complex with androgen response elements. Our overall goals are to identify the appropriate protein and DNA constructs that will allow us to co-crystallize relevant DBD- DNA complexes for structure determination. We have co-crystallized a minimal AR DBD with a 19 base-pair sequence representing a consensus response site. Because our previous work on nuclear receptor - DNA complexes has shown that the linker region between the DBD and LBD provides a significant DNA interface, we are also characterizing new AR DBDs in which the DBD is extended at its C-terminal region by various sized linker regions. These constructs are being tested for binding to DNA sequences representing various classes of androgen response elements. Finally, to understand how other types of response elements are recognized, we are testing a series of DNA duplexes for protein binding to use in upcoming co-crystallization trials.