Figure 3: Motility and shrinkage of A-lattice seam-enriched MTs.

Segmentally labelled (Lemur-tailed) A-lattice-enriched MTs with alternating Alexa-680 (red) and Alexa-488 (green) labelling were created by co-assembly of Alexa-labelled pig brain tubulin and 50 μM Mal3FL with GMPCPP. MTs were imaged moving over a surface of kinesin-1 motor protein using fluorescence microscopy (a); scale bar, 5 μm. The internal MT stripes were used to determine the actual MT velocity and the velocity distribution of B- and A-lattice-enriched MTs were plotted (b). The mean velocities of B-lattice MTs were slightly slower at 675±9 nm s⁻¹ (229) (mean±s.e.m. (n)) compared with A-lattice-enriched MTs at 707±6 nm s⁻¹ (614) (Student t-test with Welch’s correction for unequal variances, P=0.0043). Gaussian fits to the distributions are shown in (b) with mean velocities of 660±12 nm s⁻¹ (229) in A-lattice and 700±15 nm s⁻¹ (614) in B-lattice (mean±s.d. (n)).