Strains expressing mutant LC1 proteins exhibit alterations in flagellar phasing and the power/recovery stroke transition. Montages of individual sequential frames (1.67 ms apart) from high speed recordings illustrating the waveform of the cc124 wild type and a strain expressing the M182G mutant form of LC1 are shown. Flagellar of the mutant strain continually beat completely out of phase, leading to a rolling motion of the cell body of ∼50° in the plane of the flagella during the beat cycle. (bottom) Diagrams illustrating the superimposed waveforms are shown. Flagella containing mutant LC1 essentially stall for several milliseconds toward the end of the effective stroke, suggesting that they are inefficient at initiating the recovery stroke.