--- _id: '596' abstract: - lang: eng text: The human Mediator complex controls RNA polymerase II (pol II) function in ways that remain incompletely understood. Activator-Mediator binding alters Mediator structure, and these activator-induced structural shifts appear to play key roles in regulating transcription. A recent cryo-electron microscopy (EM) analysis revealed that pol II adopted a stable orientation within a Mediator-pol II-TFIIF assembly in which Mediator was bound to the activation domain of viral protein 16 (VP16). Whereas TFIIF was shown to be important for orienting pol II within this assembly, the potential role of the activator was not assessed. To determine how activator binding might affect pol II orientation, we isolated human Mediator-pol II-TFIIF complexes in which Mediator was not bound to an activator. Cryo-EM analysis of this assembly, coupled with pol II crystal structure docking, revealed that pol II binds Mediator at the same general location; however, in contrast to VP16-bound Mediator, pol II does not appear to stably orient in the absence of an activator. Variability in pol II orientation might be important mechanistically, perhaps to enable sense and antisense transcription at human promoters. Because Mediator interacts extensively with pol II, these results suggest that Mediator structural shifts induced by activator binding help stably orient pol II prior to transcription initiation. article_processing_charge: No author: - first_name: Carrie A full_name: Bernecky, Carrie A id: 2CB9DFE2-F248-11E8-B48F-1D18A9856A87 last_name: Bernecky orcid: 0000-0003-0893-7036 - first_name: Dylan full_name: Taatjes, Dylan last_name: Taatjes citation: ama: Bernecky C, Taatjes D. Activator-mediator binding stabilizes RNA polymerase II orientation within the human mediator-RNA polymerase II-TFIIF assembly. Journal of Molecular Biology. 2012;417(5):387-394. doi:10.1016/j.jmb.2012.02.014 apa: Bernecky, C., & Taatjes, D. (2012). Activator-mediator binding stabilizes RNA polymerase II orientation within the human mediator-RNA polymerase II-TFIIF assembly. Journal of Molecular Biology. Elsevier. https://doi.org/10.1016/j.jmb.2012.02.014 chicago: Bernecky, Carrie, and Dylan Taatjes. “Activator-Mediator Binding Stabilizes RNA Polymerase II Orientation within the Human Mediator-RNA Polymerase II-TFIIF Assembly.” Journal of Molecular Biology. Elsevier, 2012. https://doi.org/10.1016/j.jmb.2012.02.014. ieee: C. Bernecky and D. Taatjes, “Activator-mediator binding stabilizes RNA polymerase II orientation within the human mediator-RNA polymerase II-TFIIF assembly,” Journal of Molecular Biology, vol. 417, no. 5. Elsevier, pp. 387–394, 2012. ista: Bernecky C, Taatjes D. 2012. Activator-mediator binding stabilizes RNA polymerase II orientation within the human mediator-RNA polymerase II-TFIIF assembly. Journal of Molecular Biology. 417(5), 387–394. mla: Bernecky, Carrie, and Dylan Taatjes. “Activator-Mediator Binding Stabilizes RNA Polymerase II Orientation within the Human Mediator-RNA Polymerase II-TFIIF Assembly.” Journal of Molecular Biology, vol. 417, no. 5, Elsevier, 2012, pp. 387–94, doi:10.1016/j.jmb.2012.02.014. short: C. Bernecky, D. Taatjes, Journal of Molecular Biology 417 (2012) 387–394. date_created: 2018-12-11T11:47:24Z date_published: 2012-04-13T00:00:00Z date_updated: 2021-01-12T08:05:21Z day: '13' doi: 10.1016/j.jmb.2012.02.014 extern: '1' intvolume: ' 417' issue: '5' language: - iso: eng main_file_link: - open_access: '1' url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4582759/ month: '04' oa: 1 oa_version: None page: 387 - 394 publication: Journal of Molecular Biology publication_status: published publisher: Elsevier publist_id: '7208' status: public title: Activator-mediator binding stabilizes RNA polymerase II orientation within the human mediator-RNA polymerase II-TFIIF assembly type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 417 year: '2012' ...