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

To help understand the function of inner-arm dynein in nagellar motility, dynein samples from an outer arm-missing mutant of Chlamydomonas (odal) were examined for the ability to translocate microtubules in vitro. High-salt extract ofaxonemes 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 μm s, which were comparable to the microtubule sliding rate in disintegrating oda axonemes.