Modular and Flexible Molecular Device for Simultaneous Cytosine and Adenine Base Editing at Random Genomic Loci in Filamentous Fungi

Random base editing is regarded as a fundamental methodfor acceleratingthe genomic evolution in both scientific research and industrial applications.In this study, we designed a modular interaction-based dual base editor(MIDBE) that assembled a DNA helicase and various base editors throughdockerin/cohesin-mediated protein-protein interactions, resultingin a self-assembled MIDBE complex capable of editing bases at anylocus in the genome. The base editing type of MIDBE can be readilycontrolled by the induction of cytidine or/and adenine deaminase geneexpression. MIDBE exhibited the highest editing efficiency 2.3 x10(3) times greater than the native genomic mutation rate.To evaluate the potential of MIDBE in genomic evolution, we developeda removable plasmid-based MIDBE tool, which led to a remarkable 977.1%increase of lovastatin production in Monascus purpureus HJ11. MIDBE represents the first biological tool for generatingand accumulating base mutations in Monascus chromosome and also offersa bottom-up strategy for designing the base editor.