The kinetic mechanism of kinesin

Trends Biochem Sci. 2004 Jun;29(6):301-9. doi: 10.1016/j.tibs.2004.04.010.

Abstract

The chemical kinetic mechanism of kinesin (K) is considered by using a consensus scheme incorporating biochemically defined open, closed and trapped states. In the absence of microtubules, the dominant species is a trapped K*ADP state, which is defined by its ultra-slow release of ADP (off rate, k(off) approximately 0.002 s(-1)) and weak microtubule binding (dissociation constant, K(d) approximately 10-20 microM). Once bound, this trapped state equilibrates with a strongly binding open state that rapidly releases ADP (k(off) approximately 300 s(-1)). After ADP release, Mg*ATP binds (on rate, k(on) approximately 2 microM(-1)s(-1)) driving formation of a closed state that is defined by hydrolysis competence and by strong binding to microtubules. Hydrolysis (k(hyd) approximately 100-300 s(-1)) and phosphate release (k(off)>100 s(-1)) both occur in this microtubule-bound closed state. Phosphate release acts as a gate that controls reversion to the trapped K*ADP state, which detaches from the microtubule, completing the cycle.

Publication types

  • Review

MeSH terms

  • Adenosine Diphosphate / chemistry
  • Adenosine Triphosphate / chemistry
  • Animals
  • Humans
  • Hydrolysis
  • Kinesin / chemistry*
  • Kinetics
  • Microtubules / chemistry
  • Models, Molecular
  • Phosphates / chemistry

Substances

  • Phosphates
  • Adenosine Diphosphate
  • Adenosine Triphosphate
  • Kinesin