Reverse gyrase (original) (raw)
Reverse gyrase is a type I topoisomerase that introduces positive supercoils into DNA, contrary to the typical negative supercoils introduced by the type II topoisomerase DNA gyrase. These positive supercoils can be introduced to DNA that is either negatively supercoiled or fully relaxed. Where DNA gyrase forms a tetramer and is capable of cleaving a double-stranded region of DNA, reverse gyrase can only cleave single stranded DNA. More specifically, reverse gyrase is a member of the type IA topoisomerase class; along with the ability to relax negatively or positively supercoiled DNA (which does not require ATP), type IA enzymes also tend to have RNA-topoisomerase activities. These RNA topoisomerases help keep longer RNA strands from becoming tangled in what are referred to as "pseudoknots
| Property | Value |
|---|---|
| dbo:abstract | Reverse gyrase is a type I topoisomerase that introduces positive supercoils into DNA, contrary to the typical negative supercoils introduced by the type II topoisomerase DNA gyrase. These positive supercoils can be introduced to DNA that is either negatively supercoiled or fully relaxed. Where DNA gyrase forms a tetramer and is capable of cleaving a double-stranded region of DNA, reverse gyrase can only cleave single stranded DNA. More specifically, reverse gyrase is a member of the type IA topoisomerase class; along with the ability to relax negatively or positively supercoiled DNA (which does not require ATP), type IA enzymes also tend to have RNA-topoisomerase activities. These RNA topoisomerases help keep longer RNA strands from becoming tangled in what are referred to as "pseudoknots." Due to their ability to interact with RNA, it is thought that this is one of the most ancient class of enzymes found to date. Reverse gyrase is an ATP-dependent topoisomerase in terms of its positive supercoiling activity, however, reverse gyrase can also relax DNA strands without introducing positive supercoils through interaction with ADP. The structure of the enzyme includes both a helicase domain, which is responsible for separating nucleic acids, and a topoisomerase domain, which is responsible for the actual introduction of coils into DNA. However, mechanistic studies have shown that these two domains tend to exhibit weak activities separately and can only perform efficient DNA positive supercoiling activity when working in tandem. Other studies have also shown that reverse gyrase enzymes tend to favorably attack regions of single-stranded DNA versus double-stranded DNA, which suggests that this enzyme's critical biological function is to ensure the constant renaturation of melted DNA strands, especially in organisms that grow at high temperatures. This enzyme has been extensively characterized across several Archaea, with Sulfolobus acidocaldarius reverse gyrase being one of the first to be characterized. Additionally, it has been found that all thermophilic bacteria and archaea contain at least one reverse gyrase enzyme. Some organisms, such as members of the Crenarchaeota phylum, even have two reverse gyrase enzymes: TopR1, which tends to be active in increased temperatures, and TopR2, which shows activity in both low and high temperatures. Other exceptional organisms include Nanoarchaeum equitans, whose reverse gyrase enzyme tends to naturally exist as two separate peptides versus the typical monomeric polypeptide with a topoisomerase IA domain and a helicase domain. (en) |
| dbo:ecNumber | 5.6.2.2 |
| dbo:thumbnail | wiki-commons:Special:FilePath/Different_Classes_of_Topoisomerases.jpg?width=300 |
| dbo:wikiPageID | 71876373 (xsd:integer) |
| dbo:wikiPageLength | 17587 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 1118881196 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:Mesophile dbr:DNA_gyrase dbr:DNA_supercoil dbr:Type_I_topoisomerase dbc:Wikipedia_Student_Program dbr:Helicase dbr:Topoisomerase dbc:EC_5.99.1 dbr:Sulfolobus_solfataricus dbr:Type_II_topoisomerase dbr:Thermotoga_maritima dbr:Thermophile dbr:Positive_supercoiling dbr:File:Reverse_Gyrase_Mechanism.jpg dbr:File:Reverse_gyrase_structure_figure.jpg |
| dbp:alt | The different protein structures of various topoisomerase enzymes. Type I topoisomerases tend to be much smaller than the type II topoisomerases, as type II topoisomerases tend to be multimers, while type I topoisomerases tend to be monomers. (en) |
| dbp:caption | Molecular depictions of the different type I and type II topoisomerase classes. Reverse gyrase is indicated by the 'RG' tag under the type IA topoisomerase section of the diagram. (en) |
| dbp:casNumber | 143180 (xsd:integer) |
| dbp:ecNumber | 5.600000 (xsd:double) |
| dbp:name | Reverse gyrase (en) |
| dbp:wikiPageUsesTemplate | dbt:Infobox_enzyme dbt:Reflist |
| dct:subject | dbc:Wikipedia_Student_Program dbc:EC_5.99.1 |
| rdf:type | owl:Thing dbo:Biomolecule wikidata:Q206229 wikidata:Q8047 dbo:Enzyme |
| rdfs:comment | Reverse gyrase is a type I topoisomerase that introduces positive supercoils into DNA, contrary to the typical negative supercoils introduced by the type II topoisomerase DNA gyrase. These positive supercoils can be introduced to DNA that is either negatively supercoiled or fully relaxed. Where DNA gyrase forms a tetramer and is capable of cleaving a double-stranded region of DNA, reverse gyrase can only cleave single stranded DNA. More specifically, reverse gyrase is a member of the type IA topoisomerase class; along with the ability to relax negatively or positively supercoiled DNA (which does not require ATP), type IA enzymes also tend to have RNA-topoisomerase activities. These RNA topoisomerases help keep longer RNA strands from becoming tangled in what are referred to as "pseudoknots (en) |
| rdfs:label | Reverse gyrase (en) |
| prov:wasDerivedFrom | wikipedia-en:Reverse_gyrase?oldid=1118881196&ns=0 |
| foaf:depiction | wiki-commons:Special:FilePath/Different_Classes_of_Topoisomerases.jpg wiki-commons:Special:FilePath/Reverse_Gyrase_Mechanism.jpg wiki-commons:Special:FilePath/Reverse_gyrase_structure_figure.jpg |
| foaf:isPrimaryTopicOf | wikipedia-en:Reverse_gyrase |
| is dbo:wikiPageWikiLink of | dbr:Type_I_topoisomerase dbr:Nautilia_profundicola |
| is foaf:primaryTopic of | wikipedia-en:Reverse_gyrase |
