The tethered motor domain of a kinesin-microtubule complex catalyzes reversible synthesis of bound ATP.

ABSTRACT: Although the steps for the forward reaction of ATP hydrolysis by the motor protein kinesin have been studied extensively, the rates for the reverse reactions and thus the energy changes at each step are not as well defined. Oxygen isotopic exchange between water and P(i) was used to evaluate the reverse rates. The fraction of the kinesin x ADP x P(i) complex that reverts to ATP before release of P(i) during net hydrolysis was approximately 0 and approximately 2.6% in the absence and presence of microtubules (MTs), respectively. The rate of synthesis of bound ATP from free P(i) and the MT x kinesin x ADP complex was approximately 1.7 M(-1) x s(-1) (K0.5 ADP = 70 microM) with monomeric kinesin in the absence of net hydrolysis. Synthesis of bound ATP from the ADP of the tethered head of a dim

SUBMITTER: Hackney DD 

PROVIDER: S-EPMC1317912 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature