Steroid degradation in Comamonas testosteroni

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• 作者：Masae Horinouchi^a ; ^{masae@riken.jp} ; Toshiaki Hayashi^a ; Toshiaki Kudo^a ; ^b
• 关键词：Comamonas testosteroni ; Steroid
• 刊名：The Journal of Steroid Biochemistry and Molecular Biology
• 出版年：2012
• 期刊代码：172_09600760
• 类别：med
• 出版时间：March, 2012
• 卷：129
• 期：1-2
• 页码：4-14
• 文件大小：578 K

摘要

Steroid degradation by Comamonas testosteroni and Nocardia restrictus have been intensively studied for the purpose of obtaining materials for steroid drug synthesis. C. testosteroni degrades side chains and converts single/double bonds of certain steroid compounds to produce androsta-1,4-diene 3,17-dione or the derivative. Following 9伪-hydroxylation leads to aromatization of the A-ring accompanied by cleavage of the B-ring, and aromatized A-ring is hydroxylated at C-4 position, cleaved at 螖4 by meta-cleavage, and divided into 2-hydroxyhexa-2,4-dienoic acid (A-ring) and 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid (B,C,D-ring) by hydrolysis. Reactions and the genes involved in the cleavage and the following degradation of the A-ring are similar to those for bacterial biphenyl degradation, and 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid degradation is suggested to be mainly 尾-oxidation. Genes involved in A-ring aromatization and degradation form a gene cluster, and the genes involved in 尾-oxidation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid also comprise a large cluster of more than 10 genes. The DNA region between these two main steroid degradation gene clusters contain 3伪-hydroxysteroid dehydrogenase gene, 螖5,3-ketosteroid isomerase gene, genes for inversion of an 伪-oriented-hydroxyl group to a 尾-oriented-hydroxyl group at C-12 position of cholic acid, and genes possibly involved in the degradation of a side chain at C-17 position of cholic acid, indicating this DNA region of more than 100 kb to be a steroid degradation gene hot spot of C. testosteroni.

Article from a special issue on steroids and microorganisms.