Institute of Modern Biopharmaceuticals, School of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
Biotechnol Prog. 2013 Jul-Aug;29(4):847-52. doi: 10.1002/btpr.1740. Epub 2013 May 11.
Daptomycin is a cyclic lipopeptide natural product produced by Stretptomyces roseosporus, displaying good bactericidal activity against a wide range of gram-positive pathogens. Daptomycin contains a 13 amino acid and kynurenine (Kyn) is essential for optimal activity of daptomycin. In this study, we characterized the Kyn pathway in S. roseosporus and investigated its role in supplying precursor for daptomycin biosynthesis. Two genes (dptJ and tdo) coding for tryptophan-2,3-dioxgenase existed in the chromosome. dptJ is located in the daptomycin biosynthetic gene cluster, while tdo is in other locus. Disruption of dptJ or tdo resulted in reduced yield by ∼50%. The introduction of an additional copy of dptJ but not tdo led to enhanced production of daptomycin by 110%. Furthermore, disruption of kyn encoding kynureninase showed improved daptomycin productivity by 30%. Our results demonstrated that the enhancement of Kyn supply through metabolic engineering approach is an efficient way to increase daptomycin production.
达托霉素是一种由玫瑰孢链霉菌产生的环状脂肽天然产物，对广泛的革兰氏阳性病原体具有良好的杀菌活性。达托霉素含有 13 个氨基酸，而犬尿氨酸 (Kyn) 是达托霉素发挥最佳活性所必需的。在这项研究中，我们对玫瑰孢链霉菌中的犬尿氨酸途径进行了表征，并研究了其在为达托霉素生物合成提供前体中的作用。染色体上存在两个编码色氨酸-2,3-双加氧酶的基因 (dptJ 和 tdo)。dptJ 位于达托霉素生物合成基因簇中，而 tdo 位于其他位置。dptJ 或 tdo 的缺失导致产量降低约 50%。引入额外的 dptJ 拷贝而不是 tdo 拷贝导致达托霉素产量提高了 110%。此外，犬尿氨酸酶编码基因 kyn 的缺失使达托霉素的生产力提高了 30%。我们的结果表明，通过代谢工程方法增加犬尿氨酸的供应是提高达托霉素产量的有效途径。
