Reaction: [acyl-carrier protein] + 7 malonyl-CoA = 7 CoA + 6-hydroxymusizin-2-carbonyl-[acyl-carrier protein] + 7 CO2 + 2 H2O
Glossary: 6-hydroxymusizin = (1,6,8-trihydroxynaphthalen-2-yl)ethan-1-one
Other name(s): CrPKS1; CrPKS2; CrPKS3; CoPKS4
Systematic name: malonyl-CoA:malonyl-CoA malonyltransferase (6-hydroymusizin-2-carboxylate-forming)
Comments: The enzyme, a non-reducing iterative type I polyketide synthase, has been isolated from the mushrooms Calonarius odorifer and Calonarius rufo-olivaceus and the mould Chrysosporium merdarium. In some, but not all, cases the enzyme also contains a thioesterase domain and releases free 6-hydroxymusizin carboxylate (cf. , 6-hydroxymusizin-2-carbonyl-[acyl-carrier protein] thioesterase). Some of the enzymes also have the activity of EC 2.3.1.336, atrochrysone-2-carbonyl-[acyl-carrier protein] synthase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Thiele, W., Obermaier, S. and Muller, M. A fasciclin protein Is essential for laccase-mediated selective phenol coupling in sporandol biosynthesis. ACS Chem. Biol. 15 (2020) 844-848. [PMID: 32227858]
2. Lohr, N.A., Eisen, F., Thiele, W., Platz, L., Motter, J., Huttel, W., Gressler, M., Muller, M. and Hoffmeister, D. Unprecedented mushroom polyketide synthases produce the universal anthraquinone precursor. Angew. Chem. Int. Ed. Engl. 61 (2022) e202116142. [PMID: 35218274]
3. Lohr, N.A., Urban, M.C., Eisen, F., Platz, L., Huttel, W., Gressler, M., Muller, M. and Hoffmeister, D. The ketosynthase domain controls chain length in mushroom oligocyclic polyketide synthases. Chembiochem 24 (2023) e202200649. [PMID: 36507600]
4. Lohr, N.A., Rakhmanov, M., Wurlitzer, J.M., Lackner, G., Gressler, M. and Hoffmeister, D. Basidiomycete non-reducing polyketide synthases function independently of SAT domains. Fungal Biol Biotechnol 10 (2023) 17. [PMID: 37542286]