3BA6

Structure of the Ca2E1P phosphoenzyme intermediate of the SERCA Ca2+-ATPase

Summary for 3BA6

• Entry DOI: 10.2210/pdb3ba6/pdb
• Related: 1t5s 1t5t
• Descriptor: Sarcoplasmic/endoplasmic reticulum calcium ATPase 1, CALCIUM ION, POTASSIUM ION, ... (5 entities in total)
• Functional Keywords: membrane protein, p-type atpase, phosphoenzyme, aspartyl-phosphoanhydride, alternative splicing, atp-binding, calcium, calcium transport, endoplasmic reticulum, hydrolase, ion transport, magnesium, metal-binding, nucleotide-binding, phosphorylation, sarcoplasmic reticulum, transmembrane, transport
• Biological source: Oryctolagus cuniculus (rabbit)
• Cellular location: Endoplasmic reticulum membrane ; Multi-pass membrane protein : P04191
• Total number of polymer chains: 1
• Total formula weight: 110268.11

Authors

Picard, M.,Winther, A.M.L.,Olesen, C.,Gyrup, C.,Morth, J.P.,Oxvig, C.,Moller, J.V.,Nissen, P. (deposition date: 2007-11-07, release date: 2007-12-18, Last modification date: 2023-11-01)

Primary citation

Olesen, C.,Picard, M.,Winther, A.M.,Gyrup, C.,Morth, J.P.,Oxvig, C.,Moller, J.V.,Nissen, P.
The structural basis of calcium transport by the calcium pump.
Nature, 450:1036-1042, 2007

PubMed Abstract: The sarcoplasmic reticulum Ca2+-ATPase, a P-type ATPase, has a critical role in muscle function and metabolism. Here we present functional studies and three new crystal structures of the rabbit skeletal muscle Ca2+-ATPase, representing the phosphoenzyme intermediates associated with Ca2+ binding, Ca2+ translocation and dephosphorylation, that are based on complexes with a functional ATP analogue, beryllium fluoride and aluminium fluoride, respectively. The structures complete the cycle of nucleotide binding and cation transport of Ca2+-ATPase. Phosphorylation of the enzyme triggers the onset of a conformational change that leads to the opening of a luminal exit pathway defined by the transmembrane segments M1 through M6, which represent the canonical membrane domain of P-type pumps. Ca2+ release is promoted by translocation of the M4 helix, exposing Glu 309, Glu 771 and Asn 796 to the lumen. The mechanism explains how P-type ATPases are able to form the steep electrochemical gradients required for key functions in eukaryotic cells.

PubMed: 18075584
DOI: 10.1038/nature06418

Experimental method

X-RAY DIFFRACTION (2.8 Å)