Tong Yaojun, Whitford Christopher M, Blin Kai, Jørgensen Tue S, Weber Tilmann, Lee Sang Yup
The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
Nat Protoc. 2020 Aug;15(8):2470-2502. doi: 10.1038/s41596-020-0339-z. Epub 2020 Jul 10.
Streptomycetes are prominent sources of bioactive natural products, but metabolic engineering of the natural products of these organisms is greatly hindered by relatively inefficient genetic manipulation approaches. New advances in genome editing techniques, particularly CRISPR-based tools, have revolutionized genetic manipulation of many organisms, including actinomycetes. We have developed a comprehensive CRISPR toolkit that includes several variations of 'classic' CRISPR-Cas9 systems, along with CRISPRi and CRISPR-base editing systems (CRISPR-BEST) for streptomycetes. Here, we provide step-by-step protocols for designing and constructing the CRISPR plasmids, transferring these plasmids to the target streptomycetes, and identifying correctly edited clones. Our CRISPR toolkit can be used to generate random-sized deletion libraries, introduce small indels, generate in-frame deletions of specific target genes, reversibly suppress gene transcription, and substitute single base pairs in streptomycete genomes. Furthermore, the toolkit includes a Csy4-based multiplexing option to introduce multiple edits in a single experiment. The toolkit can be easily extended to other actinomycetes. With our protocol, it takes <10 d to inactivate a target gene, which is much faster than alternative protocols.
链霉菌是生物活性天然产物的重要来源,但这些生物体天然产物的代谢工程因相对低效的基因操作方法而受到极大阻碍。基因组编辑技术的新进展,特别是基于CRISPR的工具,彻底改变了包括放线菌在内的许多生物体的基因操作。我们开发了一套全面的CRISPR工具包,其中包括“经典”CRISPR-Cas9系统的几种变体,以及用于链霉菌的CRISPR干扰(CRISPRi)和基于CRISPR的碱基编辑系统(CRISPR-BEST)。在这里,我们提供了设计和构建CRISPR质粒、将这些质粒转移到目标链霉菌以及鉴定正确编辑克隆的详细步骤方案。我们的CRISPR工具包可用于生成随机大小的缺失文库、引入小的插入或缺失、产生特定靶基因的框内缺失、可逆地抑制基因转录以及在链霉菌基因组中替换单个碱基对。此外,该工具包包括一个基于Csy4的多重编辑选项,可在单个实验中引入多个编辑。该工具包可以很容易地扩展到其他放线菌。按照我们的方案,使靶基因失活只需不到10天,这比其他方案要快得多。