A structural model for the catalytic cycle of Ca(2+)-ATPase.

@article{Xu2002ASM,
  title={A structural model for the catalytic cycle of Ca(2+)-ATPase.},
  author={Chen Xu and William J Rice and Wanzhong He and David L. Stokes},
  journal={Journal of molecular biology},
  year={2002},
  volume={316 1},
  pages={
          201-11
        }
}
Ca(2+)-ATPase is responsible for active transport of calcium ions across the sarcoplasmic reticulum membrane. This coupling involves an ordered sequence of reversible reactions occurring alternately at the ATP site within the cytoplasmic domains, or at the calcium transport sites within the transmembrane domain. These two sites are separated by a large distance and conformational changes have long been postulated to play an important role in their coordination. To characterize the nature of… 

Figures and Tables from this paper

Structure and function of the calcium pump.
  • D. Stokes, N. Green
  • Chemistry
    Annual review of biophysics and biomolecular structure
  • 2003
TLDR
Comparisons of various structures and correlating functional data can be compared to associate the chemical changes constituting the reaction cycle with structural changes in these domains, and identify the Ca2+-ATPase domains affected by these changes.
Molecular Mechanism of the P-Type ATPases
TLDR
A nearly complete understanding of the P-type ATPase reaction mechanism is at hand, although a few details await elucidation.
Structure and mechanism of Na,K-ATPase: functional sites and their interactions.
TLDR
Evidence is related on functional sites of Na,K-ATPase for the substrate (ATP), the essential cofactor (Mg(2+) ions), and the transported cations (Na(+) and K(+)) to the molecular structure to address the central questions of mechanism of active cation transport by all P-type cation pumps.
Crystal structure of the calcium pump with a bound ATP analogue
TLDR
The crystal structure of the Ca2+ pump of skeletal muscle sarcoplasmic reticulum is described, a representative member of the P-type ATPase superfamily, with an ATP analogue, a Mg2+ and twoCa2+ ions in the respective binding sites.
Structural Studies of a Stabilized Phosphoenzyme Intermediate of Ca2+-ATPase*
TLDR
It is suggested that the stability as well as the low fluorescence of this phosphoenzyme is due to a fluorescein-mediated cross-link between two cytoplasmic domains that prevents hydrolysis of the aspartyl phosphate.
A calcium pump made visible.
  • Anthony G Lee
  • Biology, Chemistry
    Current opinion in structural biology
  • 2002
Preexisting domain motions underlie protonation-dependent structural transitions of the P-type Ca2+-ATPase.
TLDR
It is proposed that preexisting rigid-body domain motions underlie structural transitions of SERCA, where the functionally important directionality is preserved while transport site protonation controls the dominance and amplitude of motion to shift the equilibrium between the E1 and E2 states.
The Mechanics of Calcium Transport
TLDR
Roles for the A domain and M1–M3 in Ca2+ transport and inhibition are postulated to postulate the role of thapsigargin and phospholamban in the Ca2-ATPase activity.
Structural changes in the calcium pump accompanying the dissociation of calcium
TLDR
The structure of the enzyme stabilized by thapsigargin, a potent inhibitor, shows large conformation differences from that in E1Ca2+.
The sarcoplasmic Ca2+-ATPase: design of a perfect chemi-osmotic pump
TLDR
The detailed construction of the ATPase is described in terms of one membraneous and three cytosolic domains held together by a central core that mediates coupling between Ca2+-transport and ATP hydrolysis and the role of the lipid phase and the regulatory and thermodynamic aspects of the transport mechanism are reviewed.
...
...

References

SHOWING 1-10 OF 49 REFERENCES
Crystal structure of the calcium pump of sarcoplasmic reticulum at 2.6 Å resolution
TLDR
Comparison with a low-resolution electron density map of the enzyme in the absence of calcium and with biochemical data suggests that large domain movements take place during active transport.
Structure of the calcium pump from sarcoplasmic reticulum at 8-Å resolution
TLDR
A distinct cavity leads to the putative calcium-binding site, providing a plausible path for calcium release to the lumen of the sarcoplasmic reticulum.
Modeling a dehalogenase fold into the 8-A density map for Ca(2+)-ATPase defines a new domain structure.
The ATP-binding site of Ca(2+)-ATPase revealed by electron image analysis.
Three-dimensional cryo-electron microscopy of the calcium ion pump in the sarcoplasmic reticulum membrane
TLDR
The three-dimensional structure of Ca2+-ATPase in the native sarcoplasmic reticulum membrane is presented, determined by cryo-electron microscopy and helical image analysis, and shows an unexpected transmembrane organization, consisting of three distinct segments, one of which is highly inclined.
Structure of the Calcium Pump from Sarcoplasmic Reticulum at 8 Å Resolution: Architecture of the Transmembrane Helices and Localization of the Binding Site for Thapsigargin
TLDR
The structure from helical crystals at 8 A resolution is determined and thus the alpha-helical architecture of the transmembrane domain of Ca2+-ATPase is revealed and the structural consequences of its inhibition are characterized.
Three-dimensional map of the plasma membrane H+-ATPase in the open conformation
TLDR
A three-dimensional map of the H+-ATPase is obtained by electron crystallography of two-dimensional crystals grown directly on electron microscope grids and reveals ten membrane-spanning α-helices in the membrane domain, and four major cytoplasmic domains in the open conformation of the enzyme without bound ligands.
Enhanced rotational dynamics of the phosphorylation domain of the Ca-ATPase upon calcium activation.
We have used labeling conditions that permit the specific and covalent attachment of erythrosin isothiocyanate (Er-ITC) to Lys464 within the phosphorylation domain of the Ca-ATPase in skeletal
A conformational mechanism for formation of a dead-end complex by the sarcoplasmic reticulum ATPase with thapsigargin.
Locating the thapsigargin-binding site on Ca(2+)-ATPase by cryoelectron microscopy.
TLDR
A second difference density was observed at the decavanadate-binding site within the three cytoplasmic domains, which is believed to reflect an altered affinity as a result of the long-range conformational coupling that drives the reaction cycle of this family of ATP-dependent ion pumps.
...
...