Dr. Li Fan

Li Fan, Assistant Professor in the College of Natural and Agricultural Sciences at University of California - Riverside, has been selected as the R. Gaurth Hansen Alumnus Awardee for 2011. Dr. Fan worked with Dr. Laurie Kaguni in the MSU Department of Biochemistry & Molecular Biology, receiving his Ph.D in 2000.

Current research in the Fan Laboratory focuses on XPB and XPD DNA helicases important to both transcription and DNA repair. Mutations in human XPB and XPD are associated with diseases characteristics of photosensitivity plus skin cancer or premature aging. In eukaryotes, XPB and XPD are components of a ring-shaped 10-subunit transcription factor TFIIH, essential for transcription initiation and nucleotide excision repair (NER). In spite of over two decades of research, it is still not clear why TFIIH carries two helicases of opposite polarities and how XPB and XPD work inside the TFIIH complex to fulfill their biological functions. In this lecture, I will present our results of structural characterization of archaeal XPB and XPD homologs, and discuss the roles and molecular mechanisms of XPB and XPD within the architectural restriction of the TFIIH complex to open damaged DNA for the asymmetrical dual incision during NER.