Extended Data Fig. 3: Characterization of the Kif3AB-Kap3 and Kif3AC-Kap3 heterotrimer.
From: Regulation of kinesin-2 motility by its β-hairpin motif
a, Mass photometry of purified Kif3AB-Kap3. Main peak (291 ± 23 kDa, mean ± s.d.) is consistent with the theoretical mass of heterotrimer (278 kDa). b, Electron micrograph of negatively stained Kif3AB-Kap3. c, Left, AlphaFold3 models of Kif3AB-Kap3 and Kif3AC-Kap3 colored by pLDDT according to the key. PAE plots alongside. Interface 3 highlighted with black arrowhead for Kif3B and lack of equivalent interface with white arrowhead for Kif3C. Right, Close-up views of Kap3 for each model. Note interface 2 with Kap3 common to Kif3B and Kif3C and lack of interface 3 with Kif3C (black versus white arrowheads). d, Left, SDS-PAGE of purified Kif3AC-Kap3 heterotrimer following size-exclusion chromatography, peak fraction shown. Right, Kap3 co-localization assay with full-length Kif3AC (top) and with Kif3AC lacking C-terminal regions (Kif3AΔC103CΔC155; bottom). Composite TIRF images are shown of 488 nm channel (MT), 640 nm channel (Alexa-Fluor-647-labeled Kif3A) offset in y-axis by 8 pixels, and 561 nm channel (TMR-labeled Kap3) offset in y-axis by 16-pixels.
