Related Experiment Video
Updated: Aug 16, 2026

Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Published on: April 29, 2010
Initiation and release of RNA by DNA-dependent RNA polymerase
Abstract:
During in vitro transcription of T4 DNA by E. coli RNA polymerase, chain initiation stops coincidentally with synthesis at low ionic strength (0.11) with an average of one RNA chain initiated per 24S polymerase molecule. At high ionic strength (0.37), initiation as well as synthesis continues for several hours, with an average of four chains initiated per enzyme molecule in two hours. The RNA product is released from the T4 DNA template at both low and high ionic strength. At high ionic strength, however, RNA polymerase can repeatedly initiate, synthesize, and release RNA from the synthesis complex in vitro. Under both conditions, the synthesized RNA sediments at 25-44 S, has a number average chain length of 5000 to 7500 nucleotides, and a weight average chain length of 11,500 nucleotides.
Related Concept Videos
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Eukaryotic RNA Polymerases
All three eukaryotic RNAPs require specific transcription factors, of which the...
Bacterial Transcription
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription Initiation
The promoters and enhancers and their accessory proteins allow tight regulation of...
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Eukaryotic RNA Polymerases
All three eukaryotic RNAPs require specific transcription factors, of which the...

