1. Department of Medicine, University of California at San Diego, La Jolla, California 92093-0601
2. Department of Applied Biochemistry, Konkuk University, 322 Danwol-dong, Chungju-city, Chungbuk 380-701, Korea
3. Department of Molecular and Cellular Biochemistry
4. Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536