Organization of an Activator-Bound RNA Polymerase Holoenzyme
| Autor: | Xiaodong Zhang, Martin Buck, Mathieu Rappas, Patricia C. Burrows, Tillmann Pape, Daniel Bose, Siva R. Wigneshweraraj |
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| Rok vydání: | 2008 |
| Předmět: |
Models
Molecular MICROBIO PROTEINS Protein Conformation Archaeal Proteins Biology Article 03 medical and health sciences chemistry.chemical_compound Bacterial Proteins Sigma factor RNA polymerase Image Processing Computer-Assisted Promoter Regions Genetic Molecular Biology RNA polymerase II holoenzyme 030304 developmental biology 0303 health sciences DNA clamp Bacteria Activator (genetics) 030302 biochemistry & molecular biology Promoter DNA DNA-Directed RNA Polymerases Templates Genetic Cell Biology Archaea Molecular biology Cell biology Enzyme Activation RNA Polymerase Sigma 54 Protein Subunits enzymes and coenzymes (carbohydrates) chemistry bacteria Holoenzymes |
| Zdroj: | Molecular Cell |
| ISSN: | 1097-2765 |
| DOI: | 10.1016/j.molcel.2008.09.015 |
| Popis: | Transcription initiation involves the conversion from closed promoter complexes, comprising RNA polymerase (RNAP) and double-stranded promoter DNA, to open complexes, in which the enzyme is able to access the DNA template in a single-stranded form. The complex between bacterial RNAP and its major variant sigma factor sigma(54) remains as a closed complex until ATP hydrolysis-dependent remodeling by activator proteins occurs. This remodeling facilitates DNA melting and allows the transition to the open complex. Here we present cryoelectron microscopy reconstructions of bacterial RNAP in complex with sigma(54) alone, and of RNAP-sigma(54) with an AAA+ activator. Together with photo-crosslinking data that establish the location of promoter DNA within the complexes, we explain why the RNAP-sigma(54) closed complex is unable to access the DNA template and propose how the structural changes induced by activator binding can initiate conformational changes that ultimately result in formation of the open complex. |
| Databáze: | OpenAIRE |
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