Fig. 3: Conformational switching of XPD’s domains during the ATPase cycle.

Porcupine plots showing the principal conformational changes in XPD during a single cycle of ATP binding and hydrolysis. XPD domains are colored as follows: RecA1 (gold), RecA2 (blue), Arch (magenta), and Fe–S (green). Gray arrows indicate the direction of Cα atom displacements during structural transitions among the seven MSM macrostates (S1–S7): (a) S1 → S2; (b) S2 → S3; (c) S3 → S4; (d) S4 → S5; (e) S5 → S6; and (f) S6 → S7. Black arrows indicate the overall direction of large-scale domain movements. Terminal conformational states for each transition are indicated in the bottom right corner of each panel.