Both DNA gyrase and reverse gyrase are present in the hyperthermophilic bacterium Thermotoga maritima.

ABSTRACT: Like all hyperthermophiles yet tested, the bacterium Thermotoga maritima contains a reverse gyrase. Here we show that it contains also a DNA gyrase. The genes top2A and top2B encoding the two subunits of a DNA gyrase-like enzyme have been cloned and sequenced. The Top2A (type II DNA topoisomerase A protein) is more similar to GyrA (DNA gyrase A protein) than to ParC [topoisomerase IV (Topo IV) C protein]. The difference is especially striking at the C-terminal domain, which differentiates DNA gyrases from Topo IV. DNA gyrase activity was detected in T. maritima and purified to homogeneity using a novobiocin-Sepharose column. This hyperhermophilic DNA gyrase has an optimal activity around 82-86 degrees C. In contrast to plasmids from hyperthermophilic archaea, which are from relaxed to posi

SUBMITTER: Guipaud O 

PROVIDER: S-EPMC23419 | biostudies-literature | 1997 Sep

REPOSITORIES: biostudies-literature