2HQ8

Crystal structure of coelenterazine-binding protein from renilla muelleri in the ca loaded apo form

Summary for 2HQ8

• Entry DOI: 10.2210/pdb2hq8/pdb
• Related: 2HPS
• Descriptor: Coelenterazine-binding protein ca-bound apo form, CALCIUM ION (3 entities in total)
• Functional Keywords: coelenterazine-binding protein, renilla muelleri, psi, structural genomics, southeast collaboratory for structural genomics, protein structure initiative, secsg, unknown function
• Biological source: Renilla muelleri
• Total number of polymer chains: 2
• Total formula weight: 41945.77

Authors

Stepanyuk, G.,Liu, Z.J.,Vysotski, E.S.,Lee, J.,Rose, J.P.,Wang, B.C.,Southeast Collaboratory for Structural Genomics (SECSG) (deposition date: 2006-07-18, release date: 2006-09-12, Last modification date: 2024-02-14)

Primary citation

Stepanyuk, G.A.,Liu, Z.J.,Markova, S.S.,Frank, L.A.,Lee, J.,Vysotski, E.S.,Wang, B.C.
Crystal structure of coelenterazine-binding protein from Renilla muelleri at 1.7 A: why it is not a calcium-regulated photoprotein.
PHOTOCHEM.PHOTOBIOL.SCI., 7:442-447, 2008

PubMed Abstract: Bioluminescence in the sea pansy Renilla involves two distinct proteins, a Ca2+-triggered coelenterazine-binding protein (CBP), and Renilla luciferase. CBP contains one tightly bound coelenterazine molecule, which becomes available for reaction with luciferase and O2 only subsequent to Ca2+ binding. CBP belongs to the EF-hand superfamily of Ca2+-binding proteins and contains three "EF-hand" Ca2+-binding sites. The overall spatial structure of recombinant selenomethionine-labeled CBP determined at 1.7 A, is found to approximate the protein scaffold characteristic of the class of Ca2+-regulated photoproteins. Photoproteins however, catalyze molecular oxygen addition to coelenterazine producing a 2-hydroperoxycoelenterazine intermediate, which is stabilized within the binding cavity in the absence of Ca2+. Addition of Ca2+ triggers the bioluminescence reaction. However in CBP this first step of oxygen addition is not allowed. The different amino acid environments and hydrogen bond interactions within the binding cavity, are proposed to account for the different properties of the two classes of proteins.

PubMed: 18385886
DOI: 10.1039/b716535h

Experimental method

X-RAY DIFFRACTION (1.8 Å)