Chromophore formation in DsRed occurs by a branched pathway.
Like GFP, the fluorescent protein DsRed has a chromophore that forms autocatalytically within the folded protein, but the mechanism of DsRed chromophore formation has been unclear. It was proposed that an initial oxidation generates a green chromophore, and that a final oxidation yields the red chromophore. However, this model does not adequately explain why a mature DsRed sample contains a mixture of green and red chromophores. We present evidence that the maturation pathway for DsRed branches upstream of chromophore formation. After an initial oxidation step, a final oxidation to form the acylimine of the red chromophore is in kinetic competition with a dehydration to form the green chromophore. This scheme explains why green and red chromophores are alternative end points of the maturation pathway.
Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA.
Rita L
RL
Strack
Daniel E
DE
Strongin
Laurens
L
Mets
Benjamin S
BS
Glick
Robert J
RJ
Keenan
D003116:Color; D006861:Hydrogen Peroxide / Q000737:chemistry; D007700:Kinetics; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008956:Models, Chemical; D009154:Mutation; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012995:Solubility
D008164:Luminescent Proteins; C413663:fluorescent protein 583; D006861:Hydrogen Peroxide; D010100:Oxygen