title: The ancestral role of ATP hydrolysis in type II topoisomerases: prevention of DNA double-strand breaks.
abstract: Type II DNA topoisomerases (topos) catalyse changes in DNA topology by passing one double-stranded DNA segment through another. This reaction is essential to processes such as replication and transcription, but carries with it the inherent danger of permanent double-strand break (DSB) formation. All type II topos hydrolyse ATP during their reactions; however, only DNA gyrase is able to harness the free energy of hydrolysis to drive DNA supercoiling, an energetically unfavourable process. A long-standing puzzle has been to understand why the majority of type II enzymes consume ATP to support reactions that do not require a net energy input. While certain type II topos are known to 'simplify' distributions of DNA topoisomers below thermodynamic equilibrium levels, the energy required for this process is very low, suggesting that this behaviour is not the principal reason for ATP hydrolysis. Instead, we propose that the energy of ATP hydrolysis is needed to control the separation of protein-protein interfaces and prevent the accidental formation of potentially mutagenic or cytotoxic DSBs. This interpretation has parallels with the actions of a variety of molecular machines that catalyse the conformational rearrangement of biological macromolecules.
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK. bates@liv.ac.uk
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bates
authors.forename: James M
authors.initials: JM
authors.lastname: Berger
authors.forename: Anthony
authors.initials: A
authors.lastname: Maxwell
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D005075:Biological Evolution; D053903:DNA Breaks, Double-Stranded; D027081:DNA Gyrase / Q000378:metabolism; D004250:DNA Topoisomerases, Type II / Q000737:chemistry / Q000378:metabolism*; D004706:Endodeoxyribonucleases / Q000378:metabolism; D006868:Hydrolysis; D008540:Meiosis / Q000235:genetics; D011995:Recombination, Genetic; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D000255:Adenosine Triphosphate; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II; D004706:Endodeoxyribonucleases; D000099257:Meiotic Recombination Protein SPO11