SOUTHERN ILLINOIS UNIVERSITY
Our progress over the last year has prompted us to expand our approach to examine the structure of the ISWI complexes either as free complexes or bound to nucleosomes in ever increasing molecular detail and now have the additional prospect of analyzing trapped remodeling intermediates. It has become imperative for us to ask for additional support in order to take full advantage of our progress and to expand what we can learn of these remodeling complexes by using electron microscopy and X-ray diffraction techniques. We would like to use tomography and single-particle reconstruction techniques with data from conventional and cryo-EM to obtain 3-D structures of free and nucleosome bound ISW2 (307 kDa), ISW1a (222 kDa), and ISW1b (279 kDa) chromatin remodeling complexes. In concert with these studies it is also important for us to crystallize the ISW2 complex so that we can get atomic resolution of both the free and bound complexes. The timing is particularly opportune for the x-ray diffraction studies, because Mekonnen Dechassa (a former member of the Bartholomew lab) has recently graduated and joined the laboratory of Karolin Luger at Colorado State University. Drs. Luger and Dechassa are both interested in collaborating with our lab in crystallizing ISW2 and doing the x-ray diffraction studies.