Mechanical properties of tubulin intra- and inter-dimer interfaces and their implications for microtubule dynamic instability
Fig 1
Angles describing the rotation of monomers relative to each other.
A: Microtubule-bound coordinate system xyz. α-tubulins are shown in dark green, β-tubulins in light green. x-axis is radial to the microtubule axis, y-axis is tangential to microtubule, z-axis is parallel to microtubule axis. B: Schematic representation of a curved tubulin dimer and the angles that characterize the magnitude of upper subunit tilt, θ, the direction of this tilt relative to the radius of the microtubule, φ, and the twist angle δ of tubulin monomers with respect to one another. The coordinate system xyz associated with the bottom monomer is shown in blue, the system XYZ, associated with upper monomer, is red. Cyan is an auxiliary coordinate system x'y'z', which is produced by rotation of the coordinate system xyz, so the vector oz becomes aligned with OZ.