Positive supercoiling in thermophiles and mesophiles: of the good and evil.
DNA supercoiling plays essential role in maintaining proper chromosome structure, as well as the equilibrium between genome dynamics and stability under specific physicochemical and physiological conditions. In mesophilic organisms, DNA is negatively supercoiled and, until recently, positive supercoiling was considered a peculiar mark of (hyper)thermophilic archaea needed to survive high temperatures. However, several lines of evidence suggest that negative and positive supercoiling might coexist in both (hyper)thermophilic and mesophilic organisms, raising the possibility that positive supercoiling might serve as a regulator of various cellular events, such as chromosome condensation, gene expression, mitosis, sister chromatid cohesion, centromere identity and telomere homoeostasis.
Institute of Protein Biochemistry, Consiglio Nazionale delle Ricerche, Via P. Castellino 111, 80131 Naples, Italy.
Anna
A
Valenti
Giuseppe
G
Perugino
Mosè
M
Rossi
Maria
M
Ciaramella
D001105:Archaea / Q000235:genetics* / Q000502:physiology*; D004265:DNA Helicases; D026942:DNA Topoisomerases; D019641:DNA, Archaeal / Q000737:chemistry / Q000648:ultrastructure*; D004278:DNA, Superhelical / Q000235:genetics*; D006801:Humans; D009690:Nucleic Acid Conformation
D019641:DNA, Archaeal; D004278:DNA, Superhelical; D004265:DNA Helicases; D026942:DNA Topoisomerases