title: Pulsed-field gel electrophoresis does not break E. coli chromosome undergoing excision repair after UV irradiation.
abstract: We showed before that long linear DNA molecules containing single-strand interruptions and undergoing pulsed-field gel electrophoresis (PFGE) tend to break into subfragments (electrophoretic nick instability). Here we show that circular chromosomal DNA with single-strand interruptions remains in the wells during PFGE. This means that the presence of nicks in immobile circular DNA is not enough to break this DNA during PFGE. In other words, under the conditions of our study, the artifactual conversion of nicks into double-strand breaks that we detect in linear DNA does not contribute to the overall level of chromosomal fragmentation, as measured by PFGE.
authors.affiliation: Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Sharik R
authors.initials: SR
authors.lastname: Khan
authors.affiliation: Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. Electronic address: kuzminov@life.illinois.edu.
authors.forename: Andrei
authors.initials: A
authors.lastname: Kuzminov
mesh_terms: D019457:Chromosome Breakage / Q000528:radiation effects*; D002876:Chromosomes, Bacterial / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics* / Q000528:radiation effects; D004269:DNA, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D004269:DNA, Bacterial
keywords: Double-strand breaks; Nucleotide excision repair; Single-strand breaks; Ultraviolet light