Single-Molecule Real-Time 3D Imaging of the Transcription Cycle by Modulation Interferometry.
Cell
; 167(7): 1839-1852.e21, 2016 Dec 15.
Article
en En
| MEDLINE
| ID: mdl-27984731
ABSTRACT
Many essential cellular processes, such as gene control, employ elaborate mechanisms involving the coordination of large, multi-component molecular assemblies. Few structural biology tools presently have the combined spatial-temporal resolution and molecular specificity required to capture the movement, conformational changes, and subunit association-dissociation kinetics, three fundamental elements of how such intricate molecular machines work. Here, we report a 3D single-molecule super-resolution imaging study using modulation interferometry and phase-sensitive detection that achieves <2 nm axial localization precision, well below the few-nanometer-sized individual protein components. To illustrate the capability of this technique in probing the dynamics of complex macromolecular machines, we visualize the movement of individual multi-subunit E. coli RNA polymerases through the complete transcription cycle, dissect the kinetics of the initiation-elongation transition, and determine the fate of σ70 initiation factors during promoter escape. Modulation interferometry sets the stage for single-molecule studies of several hitherto difficult-to-investigate multi-molecular transactions that underlie genome regulation.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Transcripción Genética
/
Imagen Individual de Molécula
/
Interferometría
Límite:
Humans
Idioma:
En
Revista:
Cell
Año:
2016
Tipo del documento:
Article
País de afiliación:
Estados Unidos