1SL8
Calcium-loaded apo-aequorin from Aequorea victoria
Summary for 1SL8
| Entry DOI | 10.2210/pdb1sl8/pdb |
| Related | 1EJ3 1EL4 1JF0 1JF2 1QV0 1QV1 1S36 |
| Descriptor | Aequorin 1, CALCIUM ION (3 entities in total) |
| Functional Keywords | photoprotein, obelin, bioluminescence, calcium binding, ef-hand, aequorin, structural genomics, psi, protein structure initiative, southeast collaboratory for structural genomics, secsg, luminescent protein |
| Biological source | Aequorea victoria |
| Total number of polymer chains | 1 |
| Total formula weight | 22008.81 |
| Authors | Deng, L.,Markova, S.V.,Vysotski, E.S.,Liu, Z.J.,Lee, J.,Rose, J.,Wang, B.C.,Southeast Collaboratory for Structural Genomics (SECSG) (deposition date: 2004-03-05, release date: 2004-12-28, Last modification date: 2023-11-29) |
| Primary citation | Deng, L.,Vysotski, E.S.,Markova, S.V.,Liu, Z.J.,Lee, J.,Rose, J.,Wang, B.C. All three Ca2+-binding loops of photoproteins bind calcium ions: The crystal structures of calcium-loaded apo-aequorin and apo-obelin. Protein Sci., 14:663-675, 2005 Cited by PubMed Abstract: The crystal structures of calcium-loaded apo-aequorin and apo-obelin have been determined at resolutions 1.7A and 2.2 A, respectively. A calcium ion is observed in each of the three EF-hand loops that have the canonical calcium-binding sequence, and each is coordinated in the characteristic pentagonal bipyramidal configuration. The calcium-loaded apo-protein retain the same compact scaffold and overall fold as the unreacted photoproteins containing the bound substrate, 2-hyroperoxycoelenterazine, and also the same as the Ca2+-discharged obelin bound with product, coleneteramide. Nevertheless, there are easily discerned shifts in both helix and loop regions, and the shifts are not the same between the two proteins. It is suggested that these photoproteins to sense Ca2+ concentration transients and to produce their bioluminescence response on the millisecond timescale. A mechanism of intrastructural transmission of the calcium signal is proposed. PubMed: 15689515DOI: 10.1110/ps.041142905 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.7 Å) |
Structure validation
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