Overview for MACiE Entry M0128
EC Number: 126.96.36.199 (A member of the Oxidoreductases, Acting on single donors with O2 as oxidant and incorporation of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O2, With incorporation of one atom of oxygen (internal monooxygenases or internal mixed-function oxidases))
Enzyme Name: photinus-luciferin 4-monooxygenase
Biological Species: Photinus pyralis (North american firefly)
Catalytic Chain UniprotKB Accession Codes:
- P08659 - Luciferin 4-monooxygenase
Representative PDB Code: 1ba3 - FIREFLY LUCIFERASE IN COMPLEX WITH BROMOFORM (Resolution = 2.20 Å).
Display structure information
Overall Comment: Partial reactions are catalysed by two different conformations of the enzyme. Adenylation in the PheA closed conformation and thioester formation in the bAcs rotated form. Lys443 and Lys529 are located on opposite sides of the C-terminal domain of the enzyme and are each essential for only one of the partial reactions of firefly bioluminescence supporting the proposal of two different conformations catalysing the two half-reactions . The multistep oxidation of firefly luciferin results in the production of excited oxyluciferin. Luciferase modulates emission colour by controlling the resonance-based charge delocalisation of the anionic keto form of the oxyluciferin excited state. The key residues Arg218 His245 Phe247 Thr343 Ala348 and Asp422 are absolutely conserved among luciferases and have major roles in the modulation of emission colour . While CoA is not required for bioluminescence the cofactor does have a stimulatory effect on light production . ATP is also an allosteric modulator of luciferase, with two putative allosteric sites .
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Stepwise Description of the Reaction
|Step 1||The carboxylate oxygen of photinus luciferin attacks the alpha-phosphate of ATP in a nucleophilic substitution reaction, producing the pyrophosphate product.|
|Step 2||Water deprotonates the luciferin intermediate at the C4 atom resulting in a carbanionic intermediate|
|Step 3||The carbanion attacks dioxygen in a nucleophilic addition.|
|Step 4||The peroxide anion attacks the carbonyl carbon in an intramolecular nucleophilic substitution, resulting in the formation of the AMP product and a 4-membered peroxo ring intermediate.|
|Step 5||Carbon dioxide is eliminated from the intermediate with concomitant production of a photon.|
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Catalytic Residues Involved
||Location of Function
Main Chain Amide
Metal Cofactors for M0128
||MG(not in PDB)
- B. R. Branchini et al. (2005), Biochemistry, 44, 1385-1393. Mutagenesis evidence that the partial reactions of firefly bioluminescence are catalyzed by different conformations of the luciferase C-terminal domain.
- B. R. Branchini et al. (1998), Biochemistry, 37, 15311-15319. Site-directed mutagenesis of histidine 245 in firefly luciferase: a proposed model of the active site.
- V. R. Viviani (2002), Cell. Mol. Life Sci., 59, 1833-1850. The origin, diversity, and structure function relationships of insect luciferases.
- B. R. Branchini et al. (2004), Biochemistry, 43, 7255-7262. An alternative mechanism of bioluminescence color determination in firefly luciferase.
- B. R. Branchini et al. (2000), Biochemistry, 39, 5433-5440. The role of lysine 529, a conserved residue of the acyl-adenylate-forming enzyme superfamily, in firefly luciferase.
- J.-Y. Koo et al. (1978), Proc. Natl Acad. Sci. USA, 75, 30-33. Bioluminescence of the firefly: key steps in the formation of the electronically excited state for model systems.
- T. Nakatsu et al. (2006), Nature, 440, 372-376. Structural basis for the spectral difference in luciferase bioluminescence.
Homologue information for M0128 (1ba3)
MACiE Homologues (within the PDB)
MACiE Homologues (within UniprotKB/SwissProt)
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