7O3U

The crystal structure of obelin from Obelia longissima bound with v-coelenterazine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.241 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Crystal structure of semisynthetic obelin-v.

Larionova, M.D.Wu, L.Eremeeva, E.V.Natashin, P.V.Gulnov, D.V.Nemtseva, E.V.Liu, D.Liu, Z.J.Vysotski, E.S.

(2022) Protein Sci 31: 454-469

  • DOI: https://doi.org/10.1002/pro.4244
  • Primary Citation of Related Structures:  
    7O3U

  • PubMed Abstract: 

    Coelenterazine-v (CTZ-v), a synthetic derivative with an additional benzyl ring, yields a bright bioluminescence of Renilla luciferase and its "yellow" mutant with a significant shift in the emission spectrum toward longer wavelengths, which makes it the substrate of choice for deep tissue imaging. Although Ca 2+ -regulated photoproteins activated with CTZ-v also display red-shifted light emission, in contrast to Renilla luciferase their bioluminescence activities are very low, which makes photoproteins activated by CTZ-v unusable for calcium imaging. Here, we report the crystal structure of Ca 2+ -regulated photoprotein obelin with 2-hydroperoxycoelenterazine-v (obelin-v) at 1.80 Å resolution. The structures of obelin-v and obelin bound with native CTZ revealed almost no difference; only the minor rearrangement in hydrogen-bond pattern and slightly increased distances between key active site residues and some atoms of 2-hydroperoxycoelenterazine-v were found. The fluorescence quantum yield (Φ FL ) of obelin bound with coelenteramide-v (0.24) turned out to be even higher than that of obelin with native coelenteramide (0.19). Since both obelins are in effect the enzyme-substrate complexes containing the 2-hydroperoxy adduct of CTZ-v or CTZ, we reasonably assume the chemical reaction mechanisms and the yields of the reaction products (Φ R ) to be similar for both obelins. Based on these findings we suggest that low bioluminescence activity of obelin-v is caused by the low efficiency of generating an electronic excited state (Φ S ). In turn, the low Φ S value as compared to that of native CTZ might be the result of small changes in the substrate microenvironment in the obelin-v active site.


  • Organizational Affiliation

    Photobiology Laboratory, Institute of Biophysics SB RAS, Federal Research Center "Krasnoyarsk Science Center SB RAS", Krasnoyarsk, Russia.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Obelin195Obelia longissimaMutation(s): 0 
UniProt
Find proteins for Q27709 (Obelia longissima)
Explore Q27709 
Go to UniProtKB:  Q27709
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ27709
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.241 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.88α = 90
b = 42.88β = 90
c = 375.44γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2022-02-09
    Type: Initial release
  • Version 1.1: 2022-02-16
    Changes: Database references
  • Version 1.2: 2024-01-31
    Changes: Data collection, Refinement description