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Literature summary for 5.6.2.2 extracted from

  • Jamroze, A.; Perugino, G.; Valenti, A.; Rashid, N.; Rossi, M.; Akhtar, M.; Ciaramella, M.
    The reverse gyrase from Pyrobaculum calidifontis, a novel extremely thermophilic DNA topoisomerase endowed with DNA unwinding and annealing activities (2014), J. Biol. Chem., 289, 3231-3243.
    View publication on PubMedView publication on EuropePMC
Search for more literature for 5.6.2.2

Cloned(Commentary)

Cloned (Comment) Organism
expression in Escherichia coli Pyrobaculum calidifontis

Inhibitors

Inhibitors Comment Organism Structure
ATP inhibition of the ATP hydrolysis reaction at ATP concentrations higher than 0.3 mM Pyrobaculum calidifontis

Metals/Ions

Metals/Ions Comment Organism Structure
Ca2+ the enzyme requires divalent cations for catalysis: Mg2+, Ca2+, and, at much lesser extent, Co2+-supports positive supercoiling, whereas Mn2+, Zn2+, Ni2+, and Cu2+ are essentially ineffective Pyrobaculum calidifontis
Co2+ the enzyme requires divalent cations for catalysis: Mg2+, Ca2+, and, at much lesser extent, Co2+-supports positive supercoiling, whereas Mn2+, Zn2+, Ni2+, and Cu2+ are essentially ineffective Pyrobaculum calidifontis
Mg2+ the enzyme requires divalent cations for catalysis: Mg2+, Ca2+, and, at much lesser extent, Co2+-supports positive supercoiling, whereas Mn2+, Zn2+, Ni2+, and Cu2+ are essentially ineffective Pyrobaculum calidifontis
NaCl the enzyme is active over a wide range of NaCl concentrations: it catalyzes positive supercoiling from below 1 M, and shows slight relaxation activity even at 1.2 M Pyrobaculum calidifontis

Organism

Organism UniProt Comment Textmining
Pyrobaculum calidifontis A3MU01
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Purification (Commentary)

Purification (Comment) Organism
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 Pyrobaculum calidifontis

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
additional information the enzyme also catalyzes ATP-dependent unwinding of synthetic Holliday junctions and ATP-stimulated annealing of unconstrained single-stranded oligonucleotides Pyrobaculum calidifontis ?
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 ?
negatively supercoiled DNA the enzyme catalyzes a ATP-dependent DNA-positive supercoiling reaction of closed DNA plasmids. ATP is required for a correct coordination of DNA cleavage. The enzyme is able to induce positive supercoiling with ATP concentrations of 0.0001 mM. The efficiency of the reaction increases with increasing nucleotide concentrations, with an optimum between 0.1 and 1.0 mM. In the absence of ATP, the enzyme shows weak type I topoisomerase-like DNA relaxation activity. At all temperatures, relaxed and/or positive topoisomers are produced when a certain amount of the negative substrate is still present, thus suggesting that the enzyme is highly processive, i.e. it performs multiple supercoiling cycles before detaching from DNA and attacking a new substrate molecule. In the absence of ATP the enzyme shows weak type I topoisomerase-like DNA relaxation activity Pyrobaculum calidifontis positively supercoiled DNA
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 ?

Synonyms

Synonyms Comment Organism
Reverse gyrase
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 Pyrobaculum calidifontis

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
55
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 DNA unwinding assay at Pyrobaculum calidifontis

Temperature Range [°C]

Temperature Minimum [°C] Temperature Maximum [°C] Comment Organism
50 100 ATP-dependent positive supercoiling activity requires high temperature: whereas at 50 °C the enzyme shows only a weak DNA relaxation activity, both the amount and linking number of positive topoisomers increases with temperature. In reactions above 90 °C all products are highly positive, and a significant activity is seen even at 100°C Pyrobaculum calidifontis
60 80 in the absence of ATP the enzyme shows weak type I topoisomerase-like DNA relaxation activity. This activity can only be seen between 60 and 80 °C, whereas at higher temperatures the plasmid was converted into nicked form Pyrobaculum calidifontis

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
8
-
 DNA unwinding assay at Pyrobaculum calidifontis

General Information

General Information Comment Organism
physiological function the enzyme might be involved in the physiological adaptation to high growth temperature, may be involved in preservation of genome stability Pyrobaculum calidifontis