1XP5

Structure Of The (Sr)Ca2+-ATPase E2-AlF4- Form

Summary for 1XP5

• Entry DOI: 10.2210/pdb1xp5/pdb
• Related: 1T5T
• Descriptor: Sarcoplasmic/endoplasmic reticulum calcium ATPase 1, MAGNESIUM ION, TETRAFLUOROALUMINATE ION, ... (6 entities in total)
• Functional Keywords: p-type atpase, ca2+-atpase, membrane protein, aluminium fluoride, hydrolase, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Oryctolagus cuniculus (rabbit)
• Cellular location: Endoplasmic reticulum membrane; Multi-pass membrane protein: P04191
• Total number of polymer chains: 1
• Total formula weight: 110419.71

Authors

Olesen, C.,Sorensen, T.L.S.,Nielsen, R.C.,Moller, J.V.,Nissen, P. (deposition date: 2004-10-08, release date: 2005-01-04, Last modification date: 2024-04-03)

Primary citation

Olesen, C.,Sorensen, T.L.S.,Nielsen, R.C.,Moller, J.V.,Nissen, P.
Dephosphorylation of the Calcium Pump Coupled to Counterion Occlusion
Science, 306:2251-2255, 2004

PubMed Abstract: P-type ATPases extract energy by hydrolysis of adenosine triphosphate (ATP) in two steps, formation and breakdown of a covalent phosphoenzyme intermediate. This process drives active transport and countertransport of the cation pumps. We have determined the crystal structure of rabbit sarcoplasmic reticulum Ca2+ adenosine triphosphatase in complex with aluminum fluoride, which mimics the transition state of hydrolysis of the counterion-bound (protonated) phosphoenzyme. On the basis of structural analysis and biochemical data, we find this form to represent an occluded state of the proton counterions. Hydrolysis is catalyzed by the conserved Thr-Gly-Glu-Ser motif, and it exploits an associative nucleophilic reaction mechanism of the same type as phosphoryl transfer from ATP. On this basis, we propose a general mechanism of occluded transition states of Ca2+ transport and H+ countertransport coupled to phosphorylation and dephosphorylation, respectively.

PubMed: 15618517
DOI: 10.1126/science.1106289

Experimental method

X-RAY DIFFRACTION (3 Å)