title: Probing the mechanics of the complete DNA transcription cycle in real-time using optical tweezers.
abstract: RNA polymerase (RNAP) is a DNA-dependent motor protein that links ribonucleotide polymerization to force generation and DNA translocation through its active site, i.e., mechanical work. Single-molecule studies using optical tweezers have allowed researchers to probe the load-dependent ribonucleotide incorporation rate and processivity of both single-subunit viral and multisubunit prokaryotic and eukaryotic RNAPs engaged in transcription elongation. A single-molecule method is described here, which allows the complete transcription cycle (i.e., promoter binding, initiation, elongation and termination) to be followed in real-time using dual-trap optical tweezers and a unique "three-bead" geometry. This single-molecule transcription assay can be used to probe the mechanics of both stationary and moving RNAP-DNA complexes engaged in different stages of transcription.
authors.affiliation: Department of Biology, University of York, York, UK. cb17@york.ac.uk
authors.forename: Christoph G
authors.initials: CG
authors.lastname: Baumann
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cross
mesh_terms: D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D020409:Molecular Motor Proteins / Q000378:metabolism; D052898:Optical Tweezers; D014158:Transcription, Genetic / Q000235:genetics*; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D020409:Molecular Motor Proteins; D014764:Viral Proteins; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases