Earticle

초록

영어

Bacterial/fungal biosynthetic pathways of anthraquinones have been well-known, but plant anthraquinone biosynthetic pathways remain unexplored. In this paper, we identified several chalcone synthase genes predicted to associate with anthraquinone biosynthesis, through transcriptomic, metabolomic and genomic analyses of Senna occidentalis. In in-vitro assay, chalcone synthase-like (SocCHS-L2) of Senna occidentalis was identified to produce atrochrysone carboxylic acid and endocrocin anthrone through LC-MS/MS analysis. Additionally, through X-ray crystallography, we successfully got the crystal structure of free-form (2.1 Å) and substrate-bound-form (2.2 Å) of SocCHS-L2. Structural pairwise analysis revealed that SocCHS-L2 shares high similarity with TrADS (Tetradium ruticarpum, PDB ID: 5WX3) and FhCHS1 (Freesia hybrid cultivar, PDB ID: 4WUM), with approximately 56% sequence identity. SocCHS-L2 was conserved with active-site traid, Cys-His-Asn, but it shows different residual compositions. Compared with TrADS structure, SocCHS-L2 was replaced with Ile136 and Gln262, and the direction of Tyr264 side chain seems to be un-rotatable through formation of hydrogen bond with His211, only found in SocCHS-L2. The volume analysis indicates that the condensation of SocCHS-L2 has 274.1 Å3, whereas TrADS has un undetectable pocket size. Additionally, SocCHS-L2 seems to be different shape of condensation pocket with octaketide synthase (AaOKS, PDB ID: 7DTQ) from Aloe arborescens. AaOKS catalyze the condensation of eight malonyl-CoA units to produce octaketo-beta-acyl chain, same as SocCHS-L2, but it produced different product, SEK4 and SEK4b. Although the internal cavity shapes of SocCHS-L2 and AaOKS provide sufficient space to polymerize the same intermediates, the variations in the internal residues and spatial configuration explain the production of different final products.

목차

Abstract
1. Introduction
2. Materials and Methods
2.1. Bacterial over-expression and protein purification
2.2. Enzymatic assay
2.3. Crystallization and structure determination
3. Results
3.1. Over-expression and protein purification of Chalcone synthase in Senna occidentalis
3.2. Enzymatic assay and LC-ESI-MS/MS analysis
3.3. Structure determination and comparison of SocCHS-L2 structure to other type III PKS
4. Discussion
References

키워드

저자

• Woo-Haeng Lee [ Department of Life Science and Biochemical Engineering, Sun Moon University, Asan 31460, Korea ]
• Tae-Jin Oh [ Department of Life Science and Biochemical Engineering, Sun Moon University, Asan 31460, Korea ] Corresponding Author

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  선문효정학술연구회 학술대회 프로시딩

• 간기

  반년간

• 수록기간

  2023~2026

• 십진분류

  KDC 238 DDC 289