Three-dimensional EM Structure of an Intact Activator-dependent Transcription Initiation Complex
We present the experimentally determined 3D structure of an intact activator-dependent transcription initiation complex comprising the Escherichia coli catabolite activator protein (CAP), RNA polymerase holoenzyme (RNAP), and a DNA fragment containing positions -78 to +20 of a Class I CAP-dependent promoter with a CAP site at position -61.5 and a premelted transcription bubble. A 20-{angstrom} electron microscopy reconstruction was obtained by iterative projection-based matching of single particles visualized in carbon-sandwich negative stain and was fitted using atomic coordinate sets for CAP, RNAP, and DNA. The structure defines the organization of a Class I CAP-RNAP-promoter complex and supports previously proposed interactions of CAP with RNAP {alpha} subunit C-terminal domain ({alpha}CTD), interactions of {alpha}CTD with {sigma}70 region 4, interactions of CAP and RNAP with promoter DNA, and phased-DNA-bend-dependent partial wrapping of DNA around the complex. The structure also reveals the positions and shapes of species-specific domains within the RNAP {beta}{prime}, {beta}, and {sigma}70 subunits.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- DOE - OFFICE OF SCIENCE
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1019601
- Report Number(s):
- BNL-95446-2011-JA; PNASA6; TRN: US201115%%242
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Vol. 106, Issue 47; ISSN 0027-8424
- Country of Publication:
- United States
- Language:
- English
Similar Records
Photochemical cross-linking studies on the interaction of Escherichia coli RNA polymerase with T7 DNA. [Identification of subunits involved in enzyme-template interaction]
Structure of catabolite activator protein with cobalt(II) and sulfate