Protein
Quercetin 2,3-dioxygenase
Organism
Bacillus subtilis (strain 168)
Function
Performs the first step in the degradation of the flavonoid quercetin by a dioxygenase reaction. The enzyme catalyzes the cleavage of the O-heteroaromatic ring of the flavonol quercetin yielding the depside 2-protocatechuoyl-phloroglucinol carboxylic acid and carbon monoxide. This involves the remarkable dioxygenolytic cleavage of two carbon-carbon bonds.
Sequence
MKTLCTHSLPKEKMPYLLRSGEGERYLFGRQVATVMANGRSTGDLFEIVLLSGGKGDAFPLHVHKDTHEGILVLDGKLELTLDGERYLLISGDYANIPAGTPHSYRMQSHRTRLVSYTMKGNVAHLYSVIGNPYDHAEHPPYASEEVSNERFAEAAAVADIVFLDEAKPACSAKLAELTELPDGAVPYVLESGEGDRLLTGDQLHRIVAAQKNTDGQFIVVSSEGPKGDRIVDHYHEYHTETFYCLEGQMTMWTDGQEIQLNPGDFLHVPANTVHSYRLDSHYTKMVGVLVPGLFEPFFRTLGDPYEGHIFPCEPQALRFDRILQNIEALDLKVMKP