4ycl

Crystal structure of the SR CA2+-ATPASE with bound CPACrystal structure of the SR CA2+-ATPASE with bound CPA

Structural highlights 4ycl is a 1 chain structure with sequence from Oryctolagus cuniculus. This structure supersedes the now removed PDB entry 2eas. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.25Å Ligands: , , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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). Publication Abstract from PubMed Ca(2+)-ATPase of skeletal muscle sarcoplasmic reticulum is an ATP-driven Ca(2+) pump consisting of three cytoplasmic domains and 10 transmembrane helices. In the absence of Ca(2+), the three cytoplasmic domains gather to form a compact headpiece, but the ATPase is unstable without an inhibitor. Here we describe the crystal structures of Ca(2+)-ATPase in the absence of Ca(2+) stabilized with cyclopiazonic acid alone and in combination with other inhibitors. Cyclopiazonic acid is located in the transmembrane region of the protein near the cytoplasmic surface. The binding site partially overlaps with that of 2,5-di-tert-butyl-1,4-dihydroxybenzene but is separate from that of thapsigargin. The overall structure is significantly different from that stabilized with thapsigargin: The cytoplasmic headpiece is more upright, and the transmembrane helices M1-M4 are rearranged. Cyclopiazonic acid primarily alters the position of the M1' helix and thereby M2 and M4 and then M5. Because M5 is integrated into the phosphorylation domain, the whole cytoplasmic headpiece moves. These structural changes show how an event in the transmembrane domain can be transmitted to the cytoplasmic domain despite flexible links between them. They also reveal that Ca(2+)-ATPase has considerable plasticity even when fixed by a transmembrane inhibitor, presumably to accommodate thermal fluctuations. Interdomain communication in calcium pump as revealed in the crystal structures with transmembrane inhibitors.,Takahashi M, Kondou Y, Toyoshima C Proc Natl Acad Sci U S A. 2007 Apr 3;104(14):5800-5. Epub 2007 Mar 26. PMID:17389383 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also ATPase 3D structures

spinqualitylabelsall models 4ycl, resolution 3.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image