Probing transcription factor dynamics at the single-molecule level in a living cell.
2007 (English)In: Science, ISSN 0036-8075, Vol. 316, no 5828, 1191-1194 p.Article in journal (Other academic) Published
Transcription factors regulate gene expression through their binding to DNA. In a living Escherichia coli cell, we directly observed specific binding of a lac repressor, labeled with a fluorescent protein, to a chromosomal lac operator. Using single-molecule detection techniques, we measured the kinetics of binding and dissociation of the repressor in response to metabolic signals. Furthermore, we characterized the nonspecific binding to DNA, one-dimensional (1D) diffusion along DNA segments, and 3D translocation among segments through cytoplasm at the single-molecule level. In searching for the operator, a lac repressor spends ~90% of time nonspecifically bound to and diffusing along DNA with a residence time of <5 milliseconds. The methods and findings can be generalized to other nucleic acid binding proteins.
Place, publisher, year, edition, pages
2007. Vol. 316, no 5828, 1191-1194 p.
Bacterial Proteins/genetics/*metabolism, DNA; Bacterial/*metabolism, Diffusion, Escherichia coli/*genetics, Escherichia coli Proteins/*metabolism, Kinetics, Lac Operon, Luminescent Proteins/genetics/metabolism, Microscopy; Fluorescence, Operator Regions (Genetics), Protein Binding, Repressor Proteins/*metabolism, Signal Transduction
IdentifiersURN: urn:nbn:se:uu:diva-15165DOI: 10.1126/science.1141967PubMedID: 17525339OAI: oai:DiVA.org:uu-15165DiVA: diva2:42936