title: Twisted or shifted? Fluorescence measurements of late intermediates in transcription initiation by T7 RNA polymerase.
abstract: T7 RNA polymerase undergoes dramatic structural rearrangements in the transition from initiation to elongation. Two models have been proposed for promoter-bound intermediates late in the transition. (i) A subset of promoter interactions are maintained through completion of the protein conformational (twist) change, and (ii) concerted movement (shift) of all promoter-binding elements away from the growing DNA-RNA hybrid leads to an open intermediate, with large-scale domain rotations deferred until after promoter release. Fluorescence resonance energy transfer measurements provide very strong support for the latter.
authors.affiliation: Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
authors.forename: Rosemary S
authors.initials: RS
authors.lastname: Turingan
authors.forename: Karsten
authors.initials: K
authors.lastname: Theis
authors.forename: Craig T
authors.initials: CT
authors.lastname: Martin
mesh_terms: D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000235:genetics*; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D008954:Models, Biological; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics*
chemical_list: D014764:Viral Proteins; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases