Pause and rotation of F(1)-ATPase during catalysis.
F(1)-ATPase is a rotary motor enzyme in which a single ATP molecule drives a 120 degrees rotation of the central gamma subunit relative to the surrounding alpha(3)beta(3) ring. Here, we show that the rotation of F(1)-ATPase spontaneously lapses into long (approximately 30 s) pauses during steady-state catalysis. The effects of ADP-Mg and mutation on the pauses, as well as kinetic comparison with bulk-phase catalysis, strongly indicate that the paused enzyme corresponds to the inactive state of F(1)-ATPase previously known as the ADP-Mg inhibited form in which F(1)-ATPase fails to release ADP-Mg from catalytic sites. The pausing position of the gamma subunit deviates from the ATP-waiting position and is most likely the recently found intermediate 90 degrees position.
Hirono-Hara
Y
Y
Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan.
Noji
H
H
Nishiura
M
M
Muneyuki
E
E
Hara
K Y
KY
Yasuda
R
R
Kinosita
K
K
Yoshida
M
M
D000244:Adenosine Diphosphate / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry*; D002384:Catalysis; D007700:Kinetics; D008274:Magnesium / Q000737:chemistry; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000737:chemistry*
D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; D008274:Magnesium