Related Experiment Video
Updated: Jun 15, 2026
10:11
Hybrid Ensemble and Single-molecule Assay to Image the Motion of Fully Reconstituted CMG
Published on: July 26, 2024
Helicases: an overview
1Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.
Methods in Molecular Biology (Clifton, N.J.)
|March 13, 2010
Summary
Helicases are vital enzymes that unwind DNA and RNA using energy from ATP. These essential proteins are crucial for numerous cellular processes, including DNA replication and repair.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Helicases are essential enzymes critical for nucleic acid metabolism.
- They function within molecular complexes to perform specific tasks.
- These enzymes utilize nucleoside triphosphate hydrolysis for energy.
Purpose of the Study:
- To highlight the structure and activities of helicases.
- To provide examples of helicases in nucleic acid metabolism.
- To underscore the ubiquitous and conserved nature of helicases.
Main Methods:
- Review of existing literature on helicase structure and function.
- Analysis of the role of helicases in various nucleic acid processes.
- Examples drawn from established research in molecular biology.
Main Results:
- Helicases translocate along nucleic acid strands.
- They unwind double-stranded nucleic acid structures.
- Some helicases disrupt protein-nucleic acid interactions.
Conclusions:
- Helicases are indispensable for DNA replication, repair, transcription, and translation.
- Their ability to unwind nucleic acids and manage protein interactions is key.
- Helicases are fundamental, evolutionarily conserved components of cellular machinery.
Related Concept Videos
00:55DNA Helicases
DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
02:02DNA Topoisomerases
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
03:01The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or 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...
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...
03:01The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or 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...
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...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...