Ye Xueying, Wang Hui, Kan Jie, Li Jin, Huang Tongwang, Xiong Guangming, Hu Zhong
Biology Department, College of Science, Shantou University, Shantou, 515063, China.
Biology Department, College of Science, Shantou University, Shantou, 515063, China.
Chem Biol Interact. 2017 Oct 1;276:105-112. doi: 10.1016/j.cbi.2017.06.010. Epub 2017 Jun 13.
17β-hydroxysteroid dehydrogenases (17β-HSD) are a group of oxidoreductase enzymes that exhibit high specificity for 17C reduction/oxidation. However, the mechanism of 17β-HSD in oxidizing steroid hormone 17β-estradiol to estrone in bacterium is still unclear. In this work, a functional bacterium Rhodococcus sp. P14 was identified having rapid ability to oxidize estradiol into estrone in mineral salt medium (MSM) within 6 h. The functional genes encoding NADH-dependent oxidoreductase were successfully detected with the help of bioinformatics, and it was identified that it contained two consensus regions affiliated to the short-chain dehydrogenase/reductase (SDR) superfamily. Expression of 17β-HSD could be induced by estradiol in strain P14. The 17β-HSD gene from Rhodococcus sp. P14 was expressed in Escherichia coli strain BL21. Furthermore, recombinant 17β-HSD-expressing BL21 cells showed a high transformation rate, they are capable of transforming estradiol to estrone up to 94%. The purified His-17β-HSD protein also exhibited high catalyzing efficiency. In conclusion, this study provides the first evidence that a novel 17β-HSD in Rhodococcus sp. P14 can catalyze the oxidation of estradiol.
17β-羟基类固醇脱氢酶（17β-HSD）是一组对17位碳的还原/氧化具有高度特异性的氧化还原酶。然而，细菌中17β-HSD将甾体激素17β-雌二醇氧化为雌酮的机制仍不清楚。在本研究中，鉴定出一株功能菌红球菌属P14，其在矿物盐培养基（MSM）中6小时内具有将雌二醇快速氧化为雌酮的能力。借助生物信息学成功检测到编码依赖NADH的氧化还原酶的功能基因，并鉴定其包含两个属于短链脱氢酶/还原酶（SDR）超家族的共有区域。在菌株P14中，17β-HSD的表达可被雌二醇诱导。红球菌属P14的17β-HSD基因在大肠杆菌BL21菌株中表达。此外，表达重组17β-HSD的BL21细胞显示出高转化率，它们能够将雌二醇转化为雌酮，转化率高达94%。纯化的His-17β-HSD蛋白也表现出高催化效率。总之，本研究首次证明红球菌属P14中的一种新型17β-HSD可催化雌二醇的氧化。
