Figure 3 : Movements associated with constriction and opening of the active site.

From: Membrane pyrophosphatases from Thermotoga maritima and Vigna radiata suggest a conserved coupling mechanism

Figure 3

(a) Comparison of TmPPase:IDP (blue) and TmPPase:Ca:Mg (light blue). TMHs 3, 4, 5, 6, 11, 12, 13, 14, 15 and 16, which move between these two states are labelled and coloured, while the rest is in grey. Loops 5–6 and 13–14, which are visible in TmPPase:IDP but not in TmPPase:Ca:Mg, are also labelled. (b) Comparison of TmPPase:IDP and TmPPase:Pi2 (sky blue). Moving TMHs 13 and 14 are labelled and coloured. (c) Comparison of VrPPase:IDP (yellow) and VrPPase:Pi (gold). Moving TMHs 3, 4, 5, 6, 11, 12, 13 and 14 are coloured and labelled. The r.m.s.d./Cα are: resting TmPPase:Ca:Mg-TmPPase:IDP, 1.70 Å; TmPPase:Ca:Mg-TmPPase:Pi2, 1.31 Å; TmPPase:IDP-TmPPase:Pi2, 0.90 Å; VrPPase:Pi:VrPPase:IDP, 1.12 Å.