The long-range goal of this project is to define the interactions in the transcription complex that cause arrest and termination by RNA polymerase II in higher eukaryotes. Transcriptional arrest or termination contributes to gene regulation in eukaryotes, but the underlying mechanisms are unknown. To understand these mechanisms, a much better appreciation of the structure of RNA polymerase II transcription elongation complexes, both at arrest sites where elongation normally is efficient, will be required. Methods will be developed to produce defined elongation complexes that contain either pure RNA polymerase II or RNA polymerase II that carries the modifications and auxiliary factors it acquires during initiation at a promoter. Both types of defined elongation complexes will be isolated and their structures probed using a variety of agents that can reveal the configuration of RNA and DNA strands within them. Experiments will be performed to test two models for transcriptional arrest; 1) that altered configuration of the transcript produces arrest and 2) that arrest is caused by bent, or conformationally altered, DNA molecules. %%% This study will produce new insight into how RNA polymerase transcribes the information in genes (DNA) to an RNA product which is required to express genetic information.
