{"598501":{"#nid":"598501","#data":{"type":"event","title":"Single Molecule DNA-protein Interactions: From Retroviral Restriction to Nucleosome Stability","body":[{"value":"\u003Ch3\u003ESchool of Physics Soft Condensed Matter \u0026amp; Physics of Living Systems Seminar: Prof. Mark WIlliams, Northeastern University\u003C\/h3\u003E\r\n\r\n\u003Cp\u003EOptical tweezers allow us to probe the interactions of proteins with single DNA molecules and apply very small forces. Measurement of force-dependent DNA conformations allows us to quantify interactions that govern cellular function. Here we investigate the DNA interactions of human APOBEC3G, an innate antiviral immunity protein that functions as a cytidine deaminase.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EOur results show that the process of interconversion between monomeric and dimeric states regulates APOBEC3G\u0026rsquo;s deamination-dependent and deamination-independent inhibition of HIV-1 replication. I will then discuss the role of eukaryotic HMGB proteins in determining nucleosome accessibility, an important mechanism for regulating protein expression.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EWe construct an array of nucleosomes on a single DNA molecule, measuring nucleosome stability in the presence of HMGB proteins. We find significant unwrapping of nucleosomes due to HMBG-DNA binding, the extent of which differs between different types of HMGB proteins. The extent of observed destabilization correlates with the presence of nucleosome-free regions in cells, revealing distinct functions for regulation of nucleosome accessibility by different HMGB proteins.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Single Molecule DNA-protein Interactions: From Retroviral Restriction to Nucleosome Stability"}],"uid":"30957","created_gmt":"2017-11-07 18:44:24","changed_gmt":"2017-11-07 18:53:38","author":"Shaun Ashley","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2017-11-21T15:00:00-05:00","event_time_end":"2017-11-21T16:00:00-05:00","event_time_end_last":"2017-11-21T16:00:00-05:00","gmt_time_start":"2017-11-21 20:00:00","gmt_time_end":"2017-11-21 21:00:00","gmt_time_end_last":"2017-11-21 21:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"hg_media":{"598502":{"id":"598502","type":"image","title":"Prof. Mark Williams","body":null,"created":"1510080331","gmt_created":"2017-11-07 18:45:31","changed":"1510080331","gmt_changed":"2017-11-07 18:45:31","alt":"","file":{"fid":"228163","name":"Mark Wiliams northeastern univ5-2007_ed.jpg","image_path":"\/sites\/default\/files\/images\/Mark%20Wiliams%20northeastern%20univ5-2007_ed.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/Mark%20Wiliams%20northeastern%20univ5-2007_ed.jpg","mime":"image\/jpeg","size":26088,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/Mark%20Wiliams%20northeastern%20univ5-2007_ed.jpg?itok=GWU_UmzR"}}},"media_ids":["598502"],"groups":[],"categories":[],"keywords":[{"id":"960","name":"physics"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1795","name":"Seminar\/Lecture\/Colloquium"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"174045","name":"Graduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003Eshaun.ashley@physics.gatech.edu\u003C\/p\u003E\r\n","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}