Related Experiment Video
Updated: Oct 1, 2026

Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Published on: April 29, 2010
Function of DNA polymerase I in RNA-primed synthesis of bacteriophage M-13 duplex DNA
Abstract:
Cell-free extracts from Escherichia coli contain a DNA polymerase activity resistant to SH-blocking agents, which is capable of synthesizing complementary strand DNA on a circular M-13 DNA template by extension of RNA primers. This activity is considered to be identical with DNA polymerase I (or some altered form of this enzyme) since it is missing in extracts from po1A- cells. DNA synthesis in the presence of SH-blocking agents occurs at a reduced rate as compared to untreated controls and leads to the formation of DNA chains of defined size (0.4-0.5 genome's length). It is concluded that efficient M-13 duplex DNA synthesis requires the cooperation of both DNA polymerase I and III.
Related Concept Videos
The Replisome
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
Translesion DNA Polymerases
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
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...
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...
Proofreading
Errors During Replication are Corrected by the DNA Polymerase Enzyme
DNA Bacteriophages

