Table 1: Structures and states of M-PPases.

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

ProteinResolution (Å)No. chains/ASUActive site contentsClosure of active sitePosition of TMH12*
TmPPase:Ca:Mg2.62CaMgOpen: 3,400 Å30
TmPPase:IDP§3.52Mg5IDP (Na+ at ion gate)Closed: 1,600 Å3−2.7 Å
TmPPase:Pi24.02Mg4Pi2ND||−2.2 Å
TmPPase:WO4§4.02MgWO4ND||−1.0 Å
VrPPase:IDP2.62KMg5IDPClosed: 1,600 Å3−2.2 Å
VrPPase:Pi§3.54Mg2PiOpen: 2,800 Å3−0.7 Å
  1. ASU, asymmetric unit; ND, not determined.
  2. *Position relative to that in TmPPase:Ca:Mg based upon K12.50 Cα, where a negative number represents a downwards motion.
  3. Structures from Kellosalo et al.11
  4. Structure from Lin et al.12
  5. §Structures presented in this paper.
  6. ||ND because the loops are missing, meaning that the active site volume can not be meaningfully compared. ASU, asymmetric unit.