Related Experiment Video
Updated: Jun 3, 2026
05:37
Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
[The biological functions of G-quadruplex]
Zan Chen1, Ming-He Xiu, Su-Fang Li
1Institute of Vascular Medicine, Peking University Third Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China.
Sheng Li Ke Xue Jin Zhan [Progress in Physiology]
|March 23, 2011
Summary
G-quadruplex structures in DNA and RNA play crucial roles in biological processes like gene stability and regulation. This review covers recent findings on their functions in genomic DNA, RNA, and G-quadruplex oligonucleotides.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Context:
- G-quadruplexes are non-canonical nucleic acid structures.
- They are found in functional genomic regions like telomeres and promoters.
- These structures are present in both DNA and RNA.
Purpose:
- To review recent studies on G-quadruplexes.
- To focus on the biological functions of G-quadruplexes.
- To discuss G-quadruplexes in genomic DNA, RNA, and G-quadruplex oligonucleotides.
Summary:
- G-quadruplexes are specialized secondary structures in nucleic acids.
- They are implicated in critical biological processes such as gene stability, telomere synthesis, and gene expression regulation.
- This review synthesizes current research on their roles in DNA, RNA, and synthetic oligonucleotides.
Impact:
- Highlights the significance of G-quadruplexes in fundamental biological mechanisms.
- Provides insights into the regulatory roles of these structures.
- Informs future research directions in nucleic acid structural biology and its applications.
Related Concept Videos
01:03Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
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...
02:27Base-pairing and DNA Repair
Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule,
02:13Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...