title: Investigating the role of the latch in the positive supercoiling mechanism of reverse gyrase.
abstract: Reverse gyrase is the only topoisomerase known to positively supercoil DNA and the only protein unique to hyperthermophiles. The enzyme comprises an N-terminal ATPase domain and a C-terminal topoisomerase I domain, which interact to couple the hydrolysis of ATP to the overwinding of DNA. The part of the ATPase domain termed the "latch" represses topoisomerase activity in the absence of nucleotide. Here I provide evidence that the latch, in addition to its regulatory role, participates in the supercoiling mechanism during the DNA cleavage and religation steps. The latch also contributes to the coordination of ATP hydrolysis and positive supercoiling by inhibiting ATPase activity in the absence of supercoiling. The latch therefore plays an important role in the communication between the two domains of reverse gyrase.
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, United Kingdom. acrodriguez@rics.bwh.harvard.edu
authors.forename: A Chapin
authors.initials: AC
authors.lastname: Rodríguez
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D019611:Archaeoglobus fulgidus / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D004264:DNA Topoisomerases, Type I / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004278:DNA, Superhelical / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D009154:Mutation; D009690:Nucleic Acid Conformation; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion
chemical_list: D004278:DNA, Superhelical; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C041813:DNA reverse gyrase; D004264:DNA Topoisomerases, Type I