Mammalian DNA enriched for replication origins is enriched for snap-back sequences.
Using the instability of replication loops as a method for the isolation of double-stranded nascent DNA, extruded DNA enriched for replication origins was obtained and denatured. Snap-back DNA, single-stranded DNA with inverted repeats (palindromic sequences), reassociates rapidly into stem-loop structures with zero-order kinetics when conditions are changed from denaturing to renaturing, and can be assayed by chromatography on hydroxyapatite. Origin-enriched nascent DNA strands from mouse, rat and monkey cells growing either synchronously or asynchronously were purified and assayed for the presence of snap-back sequences. The results show that origin-enriched DNA is also enriched for snap-back sequences, implying that some origins for mammalian DNA replication contain or lie near palindromic sequences.
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D002845:Chromatography; D004247:DNA; D004261:DNA Replication; D004279:DNA, Viral; D000882:Haplorhini; D006882:Hydroxyapatites; D051379:Mice; D009691:Nucleic Acid Denaturation; D051381:Rats; D012091:Repetitive Sequences, Nucleic Acid; D013539:Simian virus 40
D004279:DNA, Viral; D006882:Hydroxyapatites; C022262:Okazaki fragments; D004247:DNA