Figure 4: CSC promotes the GAP activity of TBC1d5 and its interaction with Rab7.
From: Structural and mechanistic insights into regulation of the retromer coat by TBC1d5
(a) Kinetics of GTP hydrolysis for Rab7 in the absence and presence of the indicated concentrations of TBC1d5TBC. The absorbance at 360 nm reports the amount of a conjugate of GTP hydrolysis product, Pi. Solid lines represent a fit of experiment data to the pseudo-first-order Michaelis–Menten equation. (b) Calculated kobs for TBC1d5TBC or TBC1d5TBC/CSC as a function of of Rab7 concentration. Solid lines represent a linear fit between kobs and Rab7 concentration, giving rise to catalytic efficiency (kcat/Km, slope) and intrinsic rate constant (y intercept). (c) Fluorescence anisotropy direct binding assay, in which TBC1d5TBC or TBC1d5TBC/CSC was added to Alexa Fluor 488-labelled Rab7-GMPPNP. Solid lines represent a fit with changes in fluorescence anisotropy. (d) Fluorescence anisotropy direct binding assay, in which CSC or TBC1d5TBC/CSC was added to Alexa Fluor 488-labelled Rab7-GMPPNP.
