9GLF

Anthraquinone Pigment Production Regulated by Cinnamic Acid

Summary for 9GLF

• Entry DOI: 10.2210/pdb9glf/pdb
• Related: 6HXA
• Descriptor: AntI, PHENYLETHYLENECARBOXYLIC ACID, SODIUM ION, ... (8 entities in total)
• Functional Keywords: pigment biosynthesis, type ii polyketide synthase system, lyase, competitive inhibition, regulation
• Biological source: Photorhabdus luminescens
• Total number of polymer chains: 1
• Total formula weight: 46396.74

Authors

Su, L.,Schmalhofer, M.,Grammbitter, G.L.C.,Paczia, N.,Glatter, T.,Groll, M.,Bode, H.B. (deposition date: 2024-08-27, release date: 2025-07-02)

Primary citation

Su, L.,Schmalhofer, M.,Grammbitter, G.L.C.,Paczia, N.,Glatter, T.,Groll, M.,Bode, H.B.
The Isopropylstilbene Precursor Cinnamic Acid Inhibits Anthraquinone Pigment Production by Targeting AntI.
J.Am.Chem.Soc., 147:20246-20250, 2025

PubMed Abstract: strains, Gram-negative bacteria pathogenic to insect larvae, produce two signature compounds: the multifunctional isopropylstilbene (IPS), known for its antibiotic, insecticidal, and immunosuppressive activities, and orange-to-red pigmented anthraquinones (AQs), which attenuate oxidative stress. Here, we demonstrate an inverse correlation between the production of AQs and cinnamic acid (CA), the primary precursor for IPS formation in the model strain TTO1. Metabolic and proteomic analyses following CA treatment show that CA inhibits AntI, a key enzyme in the final step of AQ-256 biosynthesis. The crystal structure of AntI in complex with CA reveals that cinnamic acid functions as a competitive inhibitor by inducing specific structural rearrangements in the lyase, resulting in noncovalent, reversible inhibition. These findings provide atomic insights into the intricate regulatory control of pigment biosynthesis and the production of bioactive compounds.

PubMed: 40474393
DOI: 10.1021/jacs.5c07388

Experimental method

X-RAY DIFFRACTION (1.4 Å)