Molecular Mechanisms of Transcription through Single-Molecule Experiments

A review of the various aspects of transcription that have been addressed using methods of single-molecule detection and manipulation is studied. Whereas single-subunit viral polymerases such as T7 and SP6 RNAP can start transcription at a promoter region without additional cofactors, multi subunit bacterial and eukaryotic RNA polymerase (RNAPs) require transcription factors that aid the enzyme to recognize and bind to the promoter. Through the combination of single molecule manipulation and single-molecule fluorescence methods in the same experiment, it should be possible to follow, the internal dynamics of the polymerase or the binding of a regulatory factor and simultaneously monitor the mechanical variables of position, force, and torque. The result of these efforts will be a multidimensional picture of transcription that will provide crucial information about the relative timing of various molecular events and therefore reveal their causal connection.