7YJ8

Crystal structure of Stenoloma chusanum chalcone synthase 1 (ScCHS1) complex with Pinocembrin

Summary for 7YJ8

• Entry DOI: 10.2210/pdb7yj8/pdb
• Descriptor: chalcone synthase 1 (ScCHS1), pinocembrin (3 entities in total)
• Functional Keywords: flavonoids biosynthesis, chalcone synthase, stenoloma chusanum, transferase
• Biological source: Odontosoria chusana (Stenoloma chusanum)
• Total number of polymer chains: 1
• Total formula weight: 44762.30

Authors

Li, J.X.,Cheng, A.X.,Zhang, P. (deposition date: 2022-07-19, release date: 2022-08-24, Last modification date: 2023-11-29)

Primary citation

Ni, R.,Niu, M.,Fu, J.,Tan, H.,Zhu, T.T.,Zhang, J.,Lou, H.X.,Zhang, P.,Li, J.X.,Cheng, A.X.
Molecular and structural characterization of a promiscuous chalcone synthase from the fern species Stenoloma chusanum.
J Integr Plant Biol, 64:1935-1951, 2022

PubMed Abstract: The key enzymes involved in the flavonoid biosynthesis pathway have been extensively studied in seed plants, but relatively less in ferns. In this study, two 4-Coumarate: coenzyme A ligases (Sc4CL1 and Sc4CL2) and one novel chalcone synthase (ScCHS1) were functionally characterized by mining the Stenoloma chusanum transcriptome database. Recombinant Sc4CLs were able to esterify various hydroxycinnamic acids to corresponding acyl-coenzyme A (CoA). ScCHS1 could catalyze p-coumaroyl-CoA, cinnamoyl-CoA, caffeoyl-CoA, and feruloyl-CoA to form naringenin, pinocembrin, eriodictyol, and homoeriodictyol, respectively. Moreover, enzymatic kinetics studies revealed that the optimal substrates of ScCHS1 were feruloyl-CoA and caffeoyl-CoA, rather than p-coumaroyl-CoA, which was substantially different from the common CHSs. Crystallographic and site-directed mutagenesis experiments indicated that the amino acid residues, Leu87, Leu97, Met165, and Ile200, located in the substrate-binding pocket near the B-ring of products, could exert a significant impact on the unique catalytic activity of ScCHS1. Furthermore, overexpression of ScCHS1 in tt4 mutants could partially rescue the mutant phenotypes. Finally, ScCHS1 and Sc4CL1 were used to synthesize flavanones and flavones with multi-substituted hydroxyl and methoxyl B-ring in Escherichia coli, which can effectively eliminate the need for the cytochrome P450 hydroxylation/O-methyltransferase from simple phenylpropanoid acids. In summary, the identification of these important Stenoloma enzymes provides a springboard for the future production of various flavonoids in E. coli.

PubMed: 35920566
DOI: 10.1111/jipb.13335

Experimental method

X-RAY DIFFRACTION (2.2 Å)