What is guanine quadruplex G4 DNA?
In molecular biology, G-quadruplex secondary structures (G4) are formed in nucleic acids by sequences that are rich in guanine. They are helical in shape and contain guanine tetrads that can form from one, two or four strands.
What is DNA G-quadruplex?
G-quadruplex (G4) DNA is a stable secondary structure held together by G-G base pairs. DNA sequences capable of forming G4 DNA in vitro (G4 motifs) are enriched in ribosomal DNA and promoter regions, and at telomeres and mitotic and meiotic double-strand break (DSB) sites.
What is RNA G-quadruplex?
G-quadruplexes are extremely stable DNA or RNA secondary structures formed by sequences rich in guanine. These structures are implicated in many essential cellular processes and the number of biological functions attributed to them continues to grow.
What is the mechanism of DNA helicase?
Helicases display a remarkable versatility in their DNA unwinding mechanisms. Their biochemical abilities include structure-specific nucleic acid binding and unwinding, directional translocation, and protein interactions to seed macromolecular protein complex formation.
What is G rich sequence?
G-rich sequences (GRSs) capable of forming G-quadruplexes are found in the vicinity of polyadenylation regions and are involved in regulating 3′ end processing of mammalian pre-mRNAs.
What are G4 structures?
G-quadruplex (G4) structures are DNA tetraplexes that typically form in guanine-rich regions of genomes. Four guanine bases associate with each other through Hoogsteen hydrogen bonds to form a guanine tetrad plane (G-quartet), and then two or more G-quartet planes stack on top of each other to form a G4 structure2.
What is the molecular structure of helicase?
Helicases are motor proteins that couple the hydrolysis of nucleoside triphosphate (NTPase) to nucleic acid unwinding. The hexameric helicases have a characteristic ring-shaped structure, and all, except the eukaryotic minichromosomal maintenance (MCM) helicase, are homohexamers.
Is DNA helicase quaternary structure?
The tertiary structure of DNA Helicase is formed by interactions among the amino acid side chains in between the 3 polymers.
What types of DNA RNA sequences can or are more likely to fold a G quadruplex?
Guanine-rich DNA sequences can fold into four-stranded, noncanonical secondary structures called G-quadruplexes (G4s).
Who discovered the 3D structure of DNA?
James D. Watson and Francis Crick
A most important discovery The three dimensional structure of the complete DNA molecule was officially discovered by James D. Watson and Francis Crick in 1953.
Who made the first 3D model of DNA?
Watson and Crick brought together data from a number of researchers (including Franklin, Wilkins, Chargaff, and others) to assemble their celebrated model of the 3D structure of DNA. In 1962, James Watson, Francis Crick, and Maurice Wilkins were awarded the Nobel Prize in Medicine.
What types of DNA RNA sequences can or are more likely to fold a G-quadruplex?
What type of molecule is DNA helicase?
DNA helicase belongs to the class of biological molecules known as enzymes, which are biological catalysts.
Where are G Quadruplexes located in the human transcriptome?
Previous studies have reported an abundance of G4 in specific locations in genes, such as the 5′UTR, the 3′UTR and in the splice sites (5,12,16).
What is Watson and Crick model of DNA?
With the aid of illustrations, Watson and Crick state that their model of DNA consists of two helical strands twisted around each other in a double helix. Each strand, the authors explain, contains a chain of repeating units called nucleotides, where each nucleotide contains a sugar, a phosphate group, and a base.
What is the structure of helicase?
What do G-Quadruplexes do?
G-quadruplexes are noncanonical nucleic acid structures formed from stacked guanine tetrads. They are frequently used as building blocks and functional elements in fields such as synthetic biology and also thought to play widespread biological roles.