Andrew VanDemark, University of Pittsburgh, Biological Sciences
Host: Nathan Clark

Title:
The molecular basis of Paf1C chromatin recruitment

Abstract:
First identified in a search for RNA Polymerase II -associated factors, the 5-subunit Paf1 complex (Paf1C) is best characterized for its roles in regulating transcription elongation. The complex co-localizes with RNA Pol II from the promoter to the 3′ end of genes and has been linked to a growing list of transcription-related processes including: elongation through chromatin, histone modifications, and recruitment of factors important in transcript maturation. The domain structures of Paf1C subunits are largely undefined and have few clear homologs, making it difficult to attribute functions to individual subunits. We first set about trying to determine the molecular mechanism by which Paf1C is recruited to chromatin, examining the structures of two subunits implicated in this function, Rtf1 and Cdc73. The structures, combined with a variety of biochemical, biophysical and genetic analysis, have allowed us to identify important surfaces within Paf1C that promote chromatin recruitment and bring help localize additional Paf1C functions to chromatin. These process of structure determination for these two domains, also shed light on critical bottlenecks within the structure determination process which we will address moving forward.