【Lecture】Structural Basis for Transcription Initiation by Extracytoplasmic Function (ECF) σ Factors

Publisher:吴小军Release time:2017-09-16Browse the number:35

主题:    Structural Basis for Transcription Initiation by  Extracytoplasmic Function (ECF) σ Factors主讲人:   张余地点:   松江校区图文信息中心第一报告厅时间:   2017-09-16 09:30:00组织单位:   化学化工与生物工程学院

主讲人简介:张余,现任中科院植生所研究员,主要研究方向是基因转录结构生物学,以X射线衍射为主要手段研究转录与转录调控的分子机制,以及细菌次生代谢关键蛋白酶的催化机制。获得的荣誉有:2011-2013  Busch postdoctoral fellowship at Rutgers University;2016年入选中组部“青年千人计划”。在Journal  of Biological Chemistry、Nature等期刊发表十多篇论著。

内容摘要:Bacterial RNA polymerase employs multiple ECF σ factors  to initiatetranscription of environment-induced genes. As the most abundant  anddivergent group of σ factors, the molecular mechanism of ECF σ  factor-mediatedtranscription initiation remains elusive. In this study,  wedetermined a crystal structure of Mycobacterium tuberculosis RNAP  (σH)-promoter open complex (σH-RPo) with a fork transcription bubble at 3.05Å,  and a crystal structures of Mycobacterium tuberculosis σH-RPo with afull  transcription bubble at 3.30 Å. The structures reveal interactions ofECF σ  factors with RNAP core enzyme and with promoter DNA. Thestructures implicate  that ECF σ factors and the principal sigma factor sharecommon mechanisms for  promoter recognition, promoter melting, andpromoter escape. Sequence variations  at key regions of ECF σ factors inconcert confer their extraordinary specificity  in promoter recognition.