TY - JOUR
T1 - Staphylococcus aureus gyrase-quinolone-DNA ternary complexes fail to arrest replication fork progression in vitro
T2 - Effects of salt on the DNA binding mode and the catalytic activity of S. aureus gyrase
AU - Hiasa, Hiroshi
AU - Shea, Molly E.
AU - Richardson, Christine M.
AU - Gwynn, Michael N.
PY - 2003/3/7
Y1 - 2003/3/7
N2 - Type II topoisomerases bind to DNA at the catalytic domain across the DNA gate. DNA gyrases also bind to DNA at the non-homologous C-terminal domain of the GyrA subunit, which causes the wrapping of DNA about itself. This unique mode of DNA binding allows gyrases to introduce the negative supercoils into DNA molecules. We have investigated the biochemical characteristics of Staphylococcus aureus (S. aureus) gyrase. S. aureus gyrase is known to require high concentrations of potassium glutamate (K-Glu) for its supercoiling activity. However, high concentrations of K-Glu are not required for its relaxation and decatenation activities. This is due to the requirement of high concentrations of K-Glu for S. aureus gyrase-mediated wrapping of DNA. These results suggest that S. aureus gyrase can bind to DNA at the catalytic domain independent of K-Glu concentration, but high concentrations of K-Glu are required for the binding of the C-terminal domain of GyrA to DNA and the wrapping of DNA. Thus, salt modulates the DNA binding mode and the catalytic activity of S. aureus gyrase. Quinolone drugs can stimulate the formation of covalent S. aureus gyrase-DNA complexes, but high concentrations of K-Glu inhibit the formation of S. aureus gyrase-quinolone-DNA ternary complexes. In the absence of K-Glu, ternary complexes formed with S. aureus gyrase cannot arrest replication fork progression in vitro, demonstrating that the formation of a wrapped ternary complex is required for replication fork arrest by a S. aureus gyrase-quinolone-DNA ternary complex.
AB - Type II topoisomerases bind to DNA at the catalytic domain across the DNA gate. DNA gyrases also bind to DNA at the non-homologous C-terminal domain of the GyrA subunit, which causes the wrapping of DNA about itself. This unique mode of DNA binding allows gyrases to introduce the negative supercoils into DNA molecules. We have investigated the biochemical characteristics of Staphylococcus aureus (S. aureus) gyrase. S. aureus gyrase is known to require high concentrations of potassium glutamate (K-Glu) for its supercoiling activity. However, high concentrations of K-Glu are not required for its relaxation and decatenation activities. This is due to the requirement of high concentrations of K-Glu for S. aureus gyrase-mediated wrapping of DNA. These results suggest that S. aureus gyrase can bind to DNA at the catalytic domain independent of K-Glu concentration, but high concentrations of K-Glu are required for the binding of the C-terminal domain of GyrA to DNA and the wrapping of DNA. Thus, salt modulates the DNA binding mode and the catalytic activity of S. aureus gyrase. Quinolone drugs can stimulate the formation of covalent S. aureus gyrase-DNA complexes, but high concentrations of K-Glu inhibit the formation of S. aureus gyrase-quinolone-DNA ternary complexes. In the absence of K-Glu, ternary complexes formed with S. aureus gyrase cannot arrest replication fork progression in vitro, demonstrating that the formation of a wrapped ternary complex is required for replication fork arrest by a S. aureus gyrase-quinolone-DNA ternary complex.
UR - http://www.scopus.com/inward/record.url?scp=0037424243&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037424243&partnerID=8YFLogxK
U2 - 10.1074/jbc.M209207200
DO - 10.1074/jbc.M209207200
M3 - Article
C2 - 12511566
AN - SCOPUS:0037424243
SN - 0021-9258
VL - 278
SP - 8861
EP - 8868
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 10
ER -