This family consists of oxidoreductases involved in the synthesis of different polyketides and derivatives. Questin oxidase GedK from Aspergillus terreus catalyzes the ring cleavage of the anthraquinone questin to form benzophenone desmethylsulochrin [1]. It is part of the gene cluster that mediates the biosynthesis of geodin, an intermediate in the biosynthesis of other natural products [2]. MdpL from Emericella nidulans is part of the gene cluster that mediates the biosynthesis of monodictyphenone [3].

1: A novel anthraquinone ring cleavage enzyme from Aspergillus terreus. Fujii I, Ebizuka Y, Sankawa U; J Biochem. 1988;103:878-883. PMID:3182756

2: Heterologous reconstitution of the intact geodin gene cluster in Aspergillus nidulans through a simple and versatile PCR based approach. Nielsen MT, Nielsen JB, Anyaogu DC, Holm DK, Nielsen KF, Larsen TO, Mortensen UH; PLoS One. 2013;8:e72871. PMID:24009710

3: Characterization of the Aspergillus nidulans monodictyphenone gene cluster. Chiang YM, Szewczyk E, Davidson AD, Entwistle R, Keller NP, Wang CC, Oakley BR; Appl Environ Microbiol. 2010;76:2067-2074. PMID:20139316