Table 1 Microtubule-stimulated ATPase kinetic parameters of truncation and substitution mutants of the kinesin motor domain.

From: The structure of apo-kinesin bound to tubulin links the nucleotide cycle to movement

Construct

1–349 (ref. 11)

1–325

1–324

1–349

I325G

1–349

D231A

1–349

R190A-D231A

kcat (s−1)*

50.3±1.6

16.8±0.7

0.85±0.02

1.88±0.06

1.53±0.06

11.0±0.6

KM (μM)†

1.3±0.1

0.6±0.1

0.11±0.01

0.16±0.02

0.06±0.01

0.23±0.05

  1. *Kinetic parameters determined using nonlinear least squares to fit the variation of the ATPase rate as a function of microtubular tubulin concentration, using the Michaelis–Menten equation. Kinetic parameters are given as value±s.e. (calculated from the fit).
  2. †The lower KM of the mutants seems an indirect effect of the mutations/truncations as the neck linker is not seen to contact tubulin or microtubules in the structures determined; similar observations have been reported for other kinesin neck-linker mutants23.
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