Structural highlights
2agv is a 2 chain structure with sequence from Oryctolagus cuniculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , , , |
| Related: | 1su4, 1iwo, 1vfp, 1wpe, 1wpg |
| Activity: | Calcium-transporting ATPase, with EC number 3.6.3.8 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum |
Function
[AT2A1_RABIT] This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol to the sarcoplasmic reticulum lumen. Contributes to calcium sequestration involved in muscular excitation/contraction (By similarity).
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Ca(2+)-ATPase of sarcoplasmic reticulum is an ATP-powered Ca(2+) pump but also a H(+) pump in the opposite direction with no demonstrated functional role. Here, we report a 2.4-A-resolution crystal structure of the Ca(2+)-ATPase in the absence of Ca(2+) stabilized by two inhibitors, dibutyldihydroxybenzene, which bridges two transmembrane helices, and thapsigargin, also bound in the membrane region. Now visualized are water and several phospholipid molecules, one of which occupies a cleft between two transmembrane helices. Atomic models of the Ca(2+) binding sites with explicit hydrogens derived by continuum electrostatic calculations show how water and protons fill the space and compensate charge imbalance created by Ca(2+)-release. They suggest that H(+) countertransport is a consequence of a requirement for maintaining structural integrity of the empty Ca(2+)-binding sites. For this reason, cation countertransport is probably mandatory for all P-type ATPases and possibly accompanies transport of water as well.
Structural role of countertransport revealed in Ca(2+) pump crystal structure in the absence of Ca(2+).,Obara K, Miyashita N, Xu C, Toyoshima I, Sugita Y, Inesi G, Toyoshima C Proc Natl Acad Sci U S A. 2005 Oct 11;102(41):14489-96. Epub 2005 Sep 6. PMID:16150713[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Obara K, Miyashita N, Xu C, Toyoshima I, Sugita Y, Inesi G, Toyoshima C. Structural role of countertransport revealed in Ca(2+) pump crystal structure in the absence of Ca(2+). Proc Natl Acad Sci U S A. 2005 Oct 11;102(41):14489-96. Epub 2005 Sep 6. PMID:16150713
