He Jianxin, Dong Xinlin, Huang Yongqi, Song Shikui, Su Zhengding
Department of Biological and Food Engineering, Hubei University of Technology, Wuhan 430068, Hubei, China.
Key Laboratory of Industrial Fermentation (Ministry of Education), Key Laboratory of Industrial Microbiology of Hubei Province, Wuhan 430068, Hubei, China.
Sheng Wu Gong Cheng Xue Bao. 2023 Nov 25;39(11):4550-4562. doi: 10.13345/j.cjb.230177.
has the ability to produce steroidal intermediates known as 22-hydroxy-23, 24-bisnorchol-4-en-3-one (BA) upon the knockout of the genes for either the hydroxyacyl-CoA dehydrogenase (Hsd4A) or acyl-CoA thiolase (FadA5). In a previous study, we discovered a novel metabolite in the fermentation products when the gene was deleted. This research aims to elucidate the metabolic pathway of this metabolite through structural identification, homologous sequence analysis of the gene, phylogenetic tree analysis of . HGMS2, and gene knockout. Our findings revealed that the metabolite is a C23 metabolic intermediate, named 24-norchol-4-ene-3, 22-dione (designated as 3-OPD). It is formed when a thioesterase (TE) catalyzes the formation of a β-ketonic acid by removing CoA from the side chain of 3, 22-dioxo-25, 26-bisnorchol-4-ene-24-oyl CoA (22-O-BNC-CoA), followed by spontaneously undergoing decarboxylation. These results have the potential to contribute to the development of novel steroid intermediates.
在敲除羟酰基辅酶A脱氢酶（Hsd4A）或酰基辅酶A硫解酶（FadA5）的基因后，具有产生称为22-羟基-23,24-双降胆甾-4-烯-3-酮（BA）的甾体中间体的能力。在先前的一项研究中，当该基因被删除时，我们在发酵产物中发现了一种新的代谢物。本研究旨在通过结构鉴定、该基因的同源序列分析、HGMS2的系统发育树分析和基因敲除来阐明这种代谢物的代谢途径。我们的研究结果表明，该代谢物是一种C23代谢中间体，名为24-降胆甾-4-烯-3,22-二酮（命名为3-OPD）。它是由硫酯酶（TE）通过从3,22-二氧代-25,26-双降胆甾-4-烯-24-酰基辅酶A（22-O-BNC-CoA）的侧链上去除辅酶A催化形成β-酮酸，然后自发进行脱羧反应而形成的。这些结果有可能为新型甾体中间体的开发做出贡献。
