Fig. 2.

Enzymatic assays of AURKB or AURKC with wild-type or mutant INCENP. Mutation of the INCENP phosphorylation sites Ser893 or Ser894, or of INCENP Trp897 which is also important for Aurora kinase:INCENP binding, altered the enzymatic properties considerably. All measurements were made in triplicate. a Loss of TSS motif binding decreases the reaction rate for both AURKB and AURKC on a peptide substrate. b Quantification of the rate of reaction during the linear reaction phase of a. Error bars show standard error from the linear regression. c Measurement of initial rate of reaction (V₀) at varying peptide substrate concentrations, with curves calculated by non-linear regression (curve-fitting) to the Michaelis–Menten equation. Calculated K_M and K_cat values from non-linear regression are shown in Table 2; the mutants show significant variation in K_M but similar K_cat values (with the possible exception of S894A)