Figure 6: Conformational changes in the Transducer region in the OM+ structure.

(a) The core cMD (2–708) of the OM-A and OM-B chains were aligned. Overall, the conformations of the two chains are nearly identical (r.m.s.d.=0.31 Å); however, strands β5, β6 and β7 of the β-sheet and the elements of the Transducer region (the β-bulge and HO-β5 loop) are significantly different. The OM-A chain in this region is coloured orange and the OM-B chain is yellow-orange. Displacement of the relay helix as a result of LAH rotation is also highlighted. Note that OM (space-filling model) in the binding cleft is 35 Å from the Transducer elements. (b) Comparison of the isolated Transducer elements of OM-A (orange) and OM-B (yellow-orange) showing an increased twist, a downward shift of the HO-β5 loop and extension of the β6 and β7 strands of the sheet into the β-bulge. The arrow highlights the changes in β5 to SW-II link. These differences are between the two molecules in the same unit cell. (c) In contrast, the Apo-A (orange) and Apo-B (yellow-orange) transducer elements superimpose. The Transducer region changes shown here are not as large as those reported for cleft closure as seen in myosin V (Supplementary Fig. 4b) but are following the same trajectory.