New bioactive natural products via forced evolution

Natural products from plants and microorganisms represent a rich source of drugs for human medicine to combat infections, cancer and other diseases. Finding new natural product-based drug leads, however, is becoming more and more challenging due to the frequent re-discovery of already known compounds. Recent advances in genomics revealed an enormous hidden potential of some bacteria to produce natural products that are never detected during cultivation in standard laboratory conditions. This is due to the fact that genes governing the production of potentially novel compounds remain silent due to a strict regulation that cannot be easily identified and manipulated by conventional methods. Innovative approaches must be used to unlock this potential by waking up such genes, which will lead to the production of potentially novel drug leads. In this project we will employ recently developed approach to the activation of silent genes for biosynthesis of natural products in bacteria based on a specifically modified protein involved in DNA replication. This modified protein introduces random changes (mutations) in the bacterial genome with high efficiency, eventually generating a combination of mutations that lead to the activation of silent biosynthetic genes. This process will be controlled, so that it can be stopped after the desired effect has been achieved. Activation of silent biosynthetic genes will be detected using specially designed biological sensors, which generate easily identifiable blue pigment in response to the production of the sought after compound. Hence, we will be able to easily identify those bacteria which produce the desired natural product. The compounds from such selected bacteria will be purified and characterized to confirm their novelty. Special computer programs will be used to predict possible biological activities of the new compounds, and such predictions will be experimentally verified. We believe that this project will pave the way to the discovery of new natural products-based drugs to treat a variety of human diseases.