Acceleration of the ATP-binding rate of F1-ATPase by forcible forward rotation.

نویسندگان

  • Yuko Iko
  • Kazuhito V Tabata
  • Shouichi Sakakihara
  • Takako Nakashima
  • Hiroyuki Noji
چکیده

F1-ATPase (F1) is a reversible ATP-driven rotary motor protein. When its rotary shaft is reversely rotated, F1 produces ATP against the chemical potential of ATP hydrolysis, suggesting that F1 modulates the rate constants and equilibriums of catalytic reaction steps depending on the rotary angle of the shaft. Although the chemomechanical coupling scheme of F1 has been determined, it is unclear how individual catalytic reaction steps depend on its rotary angle. Here, we report direct evidence that the ATP-binding rate of F1 increases upon the forward rotation of the rotor, and its binding affinity to ATP is enhanced by rotation.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Mechanical modulation of catalytic power on F1-ATPase.

The conformational fluctuation of enzymes has a crucial role in reaction acceleration. However, the contribution to catalysis enhancement of individual substates with conformations far from the average conformation remains unclear. We studied the catalytic power of the rotary molecular motor F(1)-ATPase from thermophilic Bacillus PS3 as it was stalled in transient conformations far from a stabl...

متن کامل

Torque generation mechanism of F1-ATPase upon NTP binding.

Molecular machines fueled by NTP play pivotal roles in a wide range of cellular activities. One common feature among NTP-driven molecular machines is that NTP binding is a major force-generating step among the elementary reaction steps comprising NTP hydrolysis. To understand the mechanism in detail,in this study, we conducted a single-molecule rotation assay of the ATP-driven rotary motor prot...

متن کامل

A model for the cooperative free energy transduction and kinetics of ATP hydrolysis by F1-ATPase.

Although the binding change mechanism of rotary catalysis by which F1-ATPase hydrolyzes ATP has been supported by equilibrium, kinetic, and structural observations, many questions concerning the function remain unanswered. Because of the importance of this enzyme, the search for a full understanding of its mechanism is a key problem in structural biology. Making use of the results of free energ...

متن کامل

Trapping the ATP binding state leads to a detailed understanding of the F1-ATPase mechanism.

The rotary motor enzyme FoF1-ATP synthase uses the proton-motive force across a membrane to synthesize ATP from ADP and Pi (H2PO4(-)) under cellular conditions that favor the hydrolysis reaction by a factor of 2 × 10(5). This remarkable ability to drive a reaction away from equilibrium by harnessing an external force differentiates it from an ordinary enzyme, which increases the rate of reactio...

متن کامل

How subunit coupling produces the -subunit rotary motion in F1-ATPase

FoF1-ATP synthase manufactures the energy ‘‘currency,’’ ATP, of living cells. The soluble F1 portion, called F1-ATPase, can act as a rotary motor, with ATP binding, hydrolysis, and product release, inducing a torque on the -subunit. A coarse-grained plastic network model is used to show at a residue level of detail how the conformational changes of the catalytic -subunits act on the -subunit th...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • FEBS letters

دوره 583 19  شماره 

صفحات  -

تاریخ انتشار 2009