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DNA is more negatively supercoiled in bacterial plasmids than in minichromosomes isolated from budding yeast
Author(s) -
MayánSantos MaríaLuisa,
MartínezRobles MaríaDolores,
Hernández Pablo,
Krimer Dora,
Schvartzman Jorge B.
Publication year - 2007
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200700294
Subject(s) - dna supercoil , plasmid , saccharomyces cerevisiae , biology , cole1 , escherichia coli , dna , chemostat , agarose gel electrophoresis , yeast , dna replication , origin of replication , dna gyrase , microbiology and biotechnology , bacteria , genetics , gene
A series of circular shuttle vectors were constructed that could replicate and transcribe in the cells of both Escherichia coli and Saccharomyces cerevisiae . 2‐D agarose gel electrophoresis run without or in the presence of different concentrations of chloroquine (CHL) revealed that bacterial plasmids were more negatively (−) supercoiled than minichromosomes isolated from budding yeast. Attempts to increase (−) supercoiling in S. cerevisiae or to reduce it in E. coli have deleterious biological consequences. These observations indicate that DNA supercoiling can vary in different species but cells are exquisitely sensitive to sudden changes in supercoiling. In E. coli , the observation that cell growth as well as ColE1 plasmid copy number decrease when DNA relaxes suggests that supercoiling could affect cell viability by regulating the initiation of both transcription and replication.