7eg2

Crystal structure of the apoAequorin complex with (S)-daCTZ

spinqualitylabelsall models 7eg2, resolution 2.22Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7eg2 is a 16 chain structure with sequence from Aequorea victoria. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.22Å Ligands: J2X Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function AEQ2_AEQVI Ca(2+)-dependent bioluminescence photoprotein. Displays an emission peak at 470 nm (blue light). Trace amounts of calcium ion trigger the intramolecular oxidation of the chromophore, coelenterazine into coelenteramide and CO(2) with the concomitant emission of light. Publication Abstract from PubMed The Ca2+-binding photoprotein aequorin is a complex of apoAequorin (apoprotein) and (S)-2-peroxycoelenterazine. Aequorin can be regenerated by the incubation of apoAequorin with coelenterazine and molecular oxygen (O2). In this study, to investigate the molecular recognition of apoAequorin for coelenterazine using chemical probes, the chiral deaza-analogs of (S)- and (R)-deaza-CTZ (daCTZ) for coelenterazine and of (S)-2- and (R)-2-hydroxymethyl-deaza-CTZ (HM-daCTZ) for 2-peroxycoelenterazine were efficiently prepared by the improvement method. The chiral deaza-analogs of (S)-daCTZ and (S)-HM-daCTZ selectively inhibited the regeneration step to aequorin by binding the catalytic site of coelenterazine in the apoAequorin molecule. The crystal structures of the apoAequorin complexes with (S)-daCTZ and (S)-HM-daCTZ were determined, suggesting that the hydroxy moiety at the C6-hydroxyphenyl group and the carbonyl moiety of the imidazopyrazinone ring in coelenterazine are essential to bind the apoAequorin molecule through hydrogen bonding. Therefore, the chiral deaza-analogs of coelenterazine can be used as a probe to study the interaction between coelenterazine and the related proteins including photoprotein, luciferase, and coelenterazine-binding protein. Chiral deaza-coelenterazine analogs for probing a substrate-binding site in the Ca2+-binding photoprotein aequorin.,Inouye S, Sumida Y, Tomabechi Y, Taguchi J, Shirouzu M, Hosoya T PLoS One. 2021 Jun 11;16(6):e0251743. doi: 10.1371/journal.pone.0251743., eCollection 2021. PMID:34115795 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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