Microtubule translocation caused by three subspecies of inner‐arm dynein from Chlamydomonas flagella

To help understand the function of inner-arm dynein in flagellar motility, dynein samples from an outer arm-missing mutant of Chlamydomonas (oda1) were examined for the ability to translocate microtubules in vitro. High-salt extract of axonemes containing inner-arm dynein was separated by ion-exchange chromatography into 7 peak fractions with ATPase activities. Of these, three fractions containing different sets of dynein heavy chains translocated microtubules. The maximal velocities were all between 3 and 5 microns/s, which were comparable to the microtubule sliding rate in disintegrating oda axonemes.