G-quadruplex
Sign in to savethumb|400px |Structure of a G-quadruplex. Left: a G-tetrad. Right: an intramolecular G4 complex.
Article
28 sectionsContents
- History
- Topology
- Structure and functional role in genome
- Telomeric quadruplexes
- Non-telomeric quadruplexes
- Function
- Genome Regulation through formation of G-quadruplex structures
- Role of Endogenous Oxidized DNA Base Damage on G4 formation
- APE1 role in Gene Regulation
- Cancer
- Telomeres
- Promoter Regions
- Therapeutics
- Ligands which bind quadruplexes
- Quadruplex prediction techniques
- Methods for studying G-quadruplexes
- Biochemical methods
- Biophysical methods
- Role in neurological disorders
- Therapeutic approaches
- Antisense-mediated interventions
- Small-molecule ligands
- G-quadruplex-forming aptamers
- References
- Further reading
- External links
- Quadruplex websites
- Tools to predict G-quadruplex motifs
thumb|400px |Structure of a G-quadruplex. Left: a G-tetrad. Right: an intramolecular G4 complex.
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. The unimolecular forms often occur naturally near the ends of the chromosomes, better known as the telomeric regions, and in transcriptional regulatory regions of multiple genes, both in microbes and across vertebrates including oncogenes in humans. Four guanine bases can associate through Hoogsteen hydrogen bonding to form a square planar structure called a guanine tetrad (G-tetrad or G-quartet), and two or more guanine tetrads (from G-tracts, continuous runs of guanine) can stack on top of each other to form a G-quadruplex.