A Two-Subunit Type I DNA Topoisomerase (Reverse Gyrase) from an Extreme Hyperthermophile

A recently described reverse gyrase from the hyperthermophilic methanogen Methanopyrus kandleri is the only known example of a heterodimeric type I topoisomerase. The enzyme is made up of a 42-kDa subunit which covalently interacts with DNA (RgyA) and a 138-kDa subunit which binds ATP (RgyB). We hav...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 1996-01, Vol.93 (1), p.106-110
Main Authors: Krah, Regis, Kozyavkin, Sergei A., Slesarev, Alexei I., Gellert, Martin
Format: Article
Language:English
Subjects:
Adenosine triphosphatases
Amino Acid Sequence
Amino acids
Base Sequence
Biochemistry
Cloning
Cloning, Molecular
Crystal structure
Deoxyribonucleic acid
DNA
DNA probes
DNA Topoisomerases, Type I - chemistry
DNA Topoisomerases, Type II - chemistry
Enzymes
Euryarchaeota - enzymology
Genes, Bacterial
Macromolecular Substances
Methanopyrus kandleri
Models, Molecular
Molecular Sequence Data
Molecules
Nucleic acids
Open reading frames
Polymerase chain reaction
Protein Conformation
Sequence Alignment
Sequence Homology, Amino Acid
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Summary:A recently described reverse gyrase from the hyperthermophilic methanogen Methanopyrus kandleri is the only known example of a heterodimeric type I topoisomerase. The enzyme is made up of a 42-kDa subunit which covalently interacts with DNA (RgyA) and a 138-kDa subunit which binds ATP (RgyB). We have now cloned and sequenced the genes for both subunits of this enzyme. Surprisingly, the universally conserved type I topoisomerase domain [Lima, C. D., Wang, J. C. & Mondragon, A. (1994) Nature (London) 367, 138-146] which has been found as a contiguous polypeptide in the prokaryotes and eukaryotes is shared between the protomers. The subdomain with the active-site tyrosine is entirely within RgyA, whereas the subdomain implicated in noncovalent binding of the cleaved DNA strand is contained entirely in RgyB. The appearance of this unique structure in a highly conserved enzyme family supports the hypothesis that the methanogens branched from other prokaryotes and eukaryotes very early in evolution.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.93.1.106