Fig. 7.

IASL labeled myosin S1; the spin probe is located between the converter and N-terminal domains of myosin (Fig. 8). Orientational distribution of the spin probe’s z-axis within myosin in three structural states, M, apo myosin (a), M*, myosin with ADP bound (b), M**, myosin with the nucleotide analog ADP.Vi bound (distributions (c) and (d)). Both distributions (c) and (d) reflect spin probe motion about its x axis, restricted (c) and unrestricted rotation (d). Domain flexibility on the microsecond time scale is proposed to explain two distributions of the spin probe orientation in one structural state of myosin (Agafonov et al. 2008; Nesmelov et al. 2008)