Detection of cruciform extrusion in DNA by temperature-gradient gel electrophoresis.


Repetitive sequences in DNA molecules, some of which are palindromic, tend to form stable cruciforms. These are frequently located in promoter regions of a specific operon and origin of replication. Temperature gradient gel electrophoresis can be used to distinguish among various supercoiled DNA topoisomers and to ascertain whether or not the cruciform… (More)