Real-time Observation of Positive Supercoiling by Reverse Gyrase
نویسندگان
چکیده
منابع مشابه
Nucleotide- and stoichiometry-dependent DNA supercoiling by reverse gyrase.
Reverse gyrase is a unique type IA topoisomerase that can introduce positive supercoils into DNA. We have investigated some of the biochemical properties of Archaeoglobus fulgidus reverse gyrase. It can mediate three distinct supercoiling reactions depending on the adenine nucleotide cofactor that is present in the reaction. Besides the ATP-driven positive supercoiling reaction, the enzyme can ...
متن کاملCrystal structures of Thermotoga maritima reverse gyrase: inferences for the mechanism of positive DNA supercoiling
Reverse gyrase is an ATP-dependent topoisomerase that is unique to hyperthermophilic archaea and eubacteria. The only reverse gyrase structure determined to date has revealed the arrangement of the N-terminal helicase domain and the C-terminal topoisomerase domain that intimately cooperate to generate the unique function of positive DNA supercoiling. Although the structure has elicited hypothes...
متن کاملReverse gyrase—recent advances and current mechanistic understanding of positive DNA supercoiling
Reverse gyrases are topoisomerases that introduce positive supercoils into DNA in an ATP-dependent reaction. They consist of a helicase domain and a topoisomerase domain that closely cooperate in catalysis. The mechanism of the functional cooperation of these domains has remained elusive. Recent studies have shown that the helicase domain is a nucleotide-regulated conformational switch that alt...
متن کاملReverse gyrase, the two domains intimately cooperate to promote positive supercoiling.
Reverse gyrases are atypical topoisomerases present in hyperthermophiles and are able to positively supercoil a circular DNA. Despite a number of studies, the mechanism by which they perform this peculiar activity is still unclear. Sequence data suggested that reverse gyrases are composed of two putative domains, a helicase-like and a topoisomerase I, usually in a single polypeptide. Based on t...
متن کاملDirect observation of DNA overwinding by reverse gyrase.
Reverse gyrase, found in hyperthermophiles, is the only enzyme known to overwind (introduce positive supercoils into) DNA. The ATP-dependent activity, detected at >70 °C, has so far been studied solely by gel electrophoresis; thus, the reaction dynamics remain obscure. Here, we image the overwinding reaction at 71 °C under a microscope, using DNA containing consecutive 30 mismatched base pairs ...
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ژورنال
عنوان ژورنال: Biophysical Journal
سال: 2009
ISSN: 0006-3495
DOI: 10.1016/j.bpj.2008.12.1444