supercoiled dna การใช้

• Supercoiled DNA forms two structures; a plectoneme or a toroid, or a combination of both.
• Gels of plasmid preparations usually show a major band of supercoiled DNA with other fainter bands in the same lane.
• It also inhibits the nicking-closing activity on the subunit of DNA gyrase that releases the positive binding stress on the supercoiled DNA.
• The movement of the DNA may be affected by the supercoiled DNA usually moves faster than relaxed DNA because it is tightly coiled and hence more compact.
• An old standing dynamic problem is how DNA " self-replication " takes place in living cells that should involve transient uncoiling of supercoiled DNA fibers.
• A procedure that has first been derived by Levitt for the description of protein folding and later been used for supercoiled DNA by Klenin and Langowski is to compute
• Note however that the size of a circular DNA like plasmids cannot be accurately gauged using standard markers unless it has been linearized by restriction digest, alternatively a supercoiled DNA marker may be used.
• A negatively supercoiled DNA molecule will produce either a one-start left-handed helix, the toroid, or a two-start right-handed helix with terminal loops, the plectoneme.
• Since the linking number " L " of supercoiled DNA is the number of times the two strands are intertwined ( and both strands remain covalently intact ), " L " cannot change.
• Prokaryotic topoisomerase I ( topo IA ) can only relax negative supercoiled DNA, whereas eukaryotic topoisomerase I ( topo IB ) can introduce positive supercoils, separating the DNA of daughter chromosomes after DNA replication, and relax DNA.
• Intermolecular triplexes are formed between triplex-forming oligonucleotides ( TFO ) and target sequences on duplex DNA . Intramolecular triplexes are the major elements of H-DNAs, unusual DNA structures that are formed in homopurine-homopyrimidine regions of supercoiled DNAs.
• Thus, it removes supercoils when interacting with positively supercoiled DNA and introduces ( additional ) negative supercoils when binding to relaxed or negatively supercoiled DNA . Netropsin's effect on supercoiled DNA was observed in detail on single molecules using a magnetic tweezers.
• Thus, it removes supercoils when interacting with positively supercoiled DNA and introduces ( additional ) negative supercoils when binding to relaxed or negatively supercoiled DNA . Netropsin's effect on supercoiled DNA was observed in detail on single molecules using a magnetic tweezers.
• Thus, it removes supercoils when interacting with positively supercoiled DNA and introduces ( additional ) negative supercoils when binding to relaxed or negatively supercoiled DNA . Netropsin's effect on supercoiled DNA was observed in detail on single molecules using a magnetic tweezers.
• "' Trovafloxacin "'( sold as "'Trovan "'by Pfizer and "'Turvel "'by Laboratorios Almirall ) was a broad spectrum antibiotic that inhibits the uncoiling of supercoiled DNA in various bacteria by blocking the activity of DNA gyrase and topoisomerase IV . It was withdrawn from the market due to the risk of hepatotoxicity.