Department of Systems Biology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
Appl Environ Microbiol. 2011 May;77(9):3035-43. doi: 10.1128/AEM.03015-10. Epub 2011 Mar 11.
Mycophenolic acid (MPA) is the active ingredient in the increasingly important immunosuppressive pharmaceuticals CellCept (Roche) and Myfortic (Novartis). Despite the long history of MPA, the molecular basis for its biosynthesis has remained enigmatic. Here we report the discovery of a polyketide synthase (PKS), MpaC, which we successfully characterized and identified as responsible for MPA production in Penicillium brevicompactum. mpaC resides in what most likely is a 25-kb gene cluster in the genome of Penicillium brevicompactum. The gene cluster was successfully localized by targeting putative resistance genes, in this case an additional copy of the gene encoding IMP dehydrogenase (IMPDH). We report the cloning, sequencing, and the functional characterization of the MPA biosynthesis gene cluster by deletion of the polyketide synthase gene mpaC of P. brevicompactum and bioinformatic analyses. As expected, the gene deletion completely abolished MPA production as well as production of several other metabolites derived from the MPA biosynthesis pathway of P. brevicompactum. Our work sets the stage for engineering the production of MPA and analogues through metabolic engineering.
麦考酚酸（MPA）是越来越重要的免疫抑制剂药物 CellCept（罗氏）和 Myfortic（诺华）中的有效成分。尽管 MPA 的历史悠久，但它的生物合成的分子基础仍然是个谜。在这里，我们报告了聚酮合酶（PKS）MpaC 的发现，我们成功地对其进行了表征，并确定其负责短小芽孢杆菌中 MPA 的产生。MpaC 存在于短小芽孢杆菌基因组中可能是一个 25kb 的基因簇。通过针对假定的抗性基因（在这种情况下是编码 IMP 脱氢酶（IMPDH）的基因的额外拷贝），成功地对基因簇进行了定位。我们报道了通过缺失短小芽孢杆菌中的聚酮合酶基因 mpaC 克隆、测序和 MPA 生物合成基因簇的功能表征，以及生物信息学分析。正如预期的那样，基因缺失完全消除了 MPA 的产生以及短小芽孢杆菌 MPA 生物合成途径中产生的几种其他代谢物。我们的工作为通过代谢工程工程生产 MPA 和类似物奠定了基础。
