1QV0

Atomic resolution structure of obelin from Obelia longissima

Summary for 1QV0

• Entry DOI: 10.2210/pdb1qv0/pdb
• Related: 1EJ3 1EL4 1JF0 1JF2 1QV1
• Descriptor: Obelin, COBALT (II) ION, POTASSIUM ION, ... (6 entities in total)
• Functional Keywords: photoprotein, obelin, bioluminescence, atomic resolution, calcium binding, ef-hand, luminescent protein
• Biological source: Obelia longissima
• Total number of polymer chains: 1
• Total formula weight: 22943.42

Authors

Liu, Z.J.,Vysotski, E.S.,Deng, L.,Lee, J.,Rose, J.,Wang, B.C. (deposition date: 2003-08-26, release date: 2003-11-11, Last modification date: 2023-08-16)

Primary citation

Liu, Z.J.,Vysotski, E.S.,Deng, L.,Lee, J.,Rose, J.,Wang, B.C.
Atomic resolution structure of obelin: soaking with calcium enhances electron density of the second oxygen atom substituted at the C2-position of coelenterazine.
Biochem.Biophys.Res.Commun., 311:433-439, 2003

PubMed Abstract: The spatial structure of the Ca(2+)-regulated photoprotein obelin has been solved to resolution of 1.1A. Two oxygen atoms are revealed substituted at the C2-position of the coelenterazine in contrast to the obelin structure at 1.73A resolution where one oxygen atom only was disclosed. The electron density of the second oxygen atom was very weak but after exposing the crystals to a trace of Ca(2+), the electron densities of both oxygen atoms became equally intense. In addition, one Ca(2+) was found bound in the loop of the first EF-hand motif. Four of the ligands were provided by protein residues Asp30, Asn32, Asn34, and the main chain oxygen of Lys36. The other two were from water molecules. From a comparison of B-factors for the residues constituting the active site, it is suggested that the variable electron densities observed in various photoprotein structures could be attributed to different mobilities of the peroxy oxygen atoms.

PubMed: 14592432
DOI: 10.1016/j.bbrc.2003.09.231

Experimental method

X-RAY DIFFRACTION (1.1 Å)