This target belongs to the the 2-oxoglutarate (2OG) and Fe(II)-dependent oxygenase superfamily. Genthreadre's most confident hits bind 1 ascorbate and 1 iron ion per subunit, but unfortunately there are no complexes with the former cofactor. Contacts with Fe are well conserved among available templates: His190, Asp192 and His247.
The closest template 1gp6A0 is bound to just one of its natural substrates, but the same protei was also solved in complex with both of them - PDB code 2brt bound to 2-oxoglutaric acid and naringenin. All but one of the template residues in contact with the former compound are identically conserved: Phe37, Tyr175, His190, Asp192, His247, Arg261, Ser263 and Phe267. I would not specify contacts from other potential substrates - such as quercetin - as they are not conserved, due to functional divergence.

TARGET T0573\\
AUTHOR 7656-5034-1890\\
REMARK Sequence consensus of contacts between homologous structures and ligands\\
METHOD pGenTHREADER and PDBSum and CSA data mining\\
Binding site: 37, 175, 190, 192, 247, 261, 263, 267\\