Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of Graph Search.
Concept
Rolling circle replication
Summary
Rolling circle replication (RCR) is a process of unidirectional nucleic acid replication that can rapidly synthesize multiple copies of circular molecules of DNA or RNA, such as plasmids, the genomes of bacteriophages, and the circular RNA genome of viroids. Some eukaryotic viruses also replicate their DNA or RNA via the rolling circle mechanism.
As a simplified version of natural rolling circle replication, an isothermal DNA amplification technique, rolling circle amplification was developed. The RCA mechanism is widely used in molecular biology and biomedical nanotechnology, especially in the field of biosensing (as a method of signal amplification).
Rolling circle DNA replication is initiated by an initiator protein encoded by the plasmid or bacteriophage DNA, which nicks one strand of the double-stranded, circular DNA molecule at a site called the double-strand origin, or DSO. The initiator protein remains bound to the 5' phosphate end of the nicked strand, and the free 3' hydroxyl end is released to serve as a primer for DNA synthesis by DNA polymerase III. Using the unnicked strand as a template, replication proceeds around the circular DNA molecule, displacing the nicked strand as single-stranded DNA. Displacement of the nicked strand is carried out by a host-encoded helicase called PcrA (the abbreviation standing for plasmid copy reduced) in the presence of the plasmid replication initiation protein.
Continued DNA synthesis can produce multiple single-stranded linear copies of the original DNA in a continuous head-to-tail series called a concatemer. These linear copies can be converted to double-stranded circular molecules through the following process:
First, the initiator protein makes another nick in the DNA to terminate synthesis of the first (leading) strand. RNA polymerase and DNA polymerase III then replicate the single-stranded origin (SSO) DNA to make another double-stranded circle. DNA polymerase I removes the primer, replacing it with DNA, and DNA ligase joins the ends to make another molecule of double-stranded circular DNA.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related courses (1)
CH-319: Experimental biochemistry and biophysics
A 7-week long (4+8 h) experiment where you plan and construct a fluorescent sensor protein starting from DNA bricks. The protein will be expressed in and purified from E.coli, characterized by bioche
Related lectures (15)
DNA Replication: Mechanisms and Applications
Explores DNA replication, the genetic code, PCR applications, and forensic testing.
DNA Replication and Transcription
Explores DNA replication, transcription, and translation processes in genetic information flow.
Biochemistry: Test Exam
Covers enzymes, evolution, lipids, and proteins in biochemistry.
Related publications (65)
Related people (10)
Related concepts (1)
Plasmid
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms. In nature, plasmids often carry genes that benefit the survival of the organism and confer selective advantage such as antibiotic resistance.
Related MOOCs (3)
Micro and Nanofabrication (MEMS)
Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.
Microstructure Fabrication Technologies I
Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.
Micro and Nanofabrication (MEMS)
Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.