The origin of luciferase activity in Zophobas mealworm AMP/CoA-ligase (protoluciferase): luciferin stereoselectivity as a switch for the oxygenase activity.
Beetle luciferases evolved from AMP/CoA-ligases. However, it is unclear how the new luciferase activity evolved. In order to clarify this question, we compared the luminescence and catalytic properties of a recently cloned luciferase-like enzyme from Zophobas mealworm, an AMP/CoA-ligase displaying weak luminescence activity, with those of cloned luciferases from the three main families of luminescent beetles: Phrixthrix hirtus railroad worm; Pyrearinus termitilluminans click beetle and Photinus pyralis firefly. The catalytic constant of the mealworm enzyme was 2-4 orders of magnitude lower than that of beetle luciferases, but 3 orders of magnitude above the non-catalyzed chemiluminescence of luciferyl-adenylate in buffer. Studies with D- and L-luciferin and their adenylates show that the luminescence reaction of the luciferase-like enzyme and beetle luciferases are stereoselective for D-luciferin and its adenylate, and that the selectivity is determined mainly at the adenylation step. Modelling studies showed that the luciferin binding site cavity of this enzyme is smaller and more hydrophobic than that of beetle luciferases. Therefore Zophobas mealworm enzyme displays true luciferase activity, keeping the attributes of an ancient protoluciferase. These results suggest that stereoselectivity for D-luciferin may have been a key event for the origin of oxygenase/luciferase activity in AMP/CoA-ligases, and that efficient luciferase activity may have further evolved mainly by increasing the catalytic constant of the oxidative reaction and the quantum yield of bioluminescence.
Laboratório de Bioquímica e Biotecnologia de Sistemas Bioluminescentes, Universidade Federal de São Carlos (UFSCAR), Campus de Sorocaba, Sorocaba, SP, Brazil. viviani@ufscar.br
Vadim R
VR
Viviani
Valeria
V
Scorsato
Rogilene A
RA
Prado
Jose G C
JG
Pereira
Kazuki
K
Niwa
Yoshihiro
Y
Ohmiya
João A R G
JA
Barbosa
D000249:Adenosine Monophosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D055162:Biocatalysis; D003198:Computer Simulation; D049454:Firefly Luciferin / Q000737:chemistry / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism*; D008156:Luciferases / Q000737:chemistry / Q000378:metabolism*; D049408:Luminescent Agents / Q000737:chemistry / Q000378:metabolism; D008163:Luminescent Measurements; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013237:Stereoisomerism; D013712:Tenebrio / Q000201:enzymology*
D019476:Insect Proteins; D049408:Luminescent Agents; D000249:Adenosine Monophosphate; D049454:Firefly Luciferin; D010105:Oxygenases; D008156:Luciferases