清华陈国强团队1天内完成蛋白质定向进化，速度提升150万倍，攻克非模式生物改造难题！

Core Viewpoint - The article discusses the development of a novel orthogonal transcription mutation system (OTM) by a research team led by Professor Chen Guoqiang from Tsinghua University, which significantly accelerates in vivo protein evolution and addresses limitations of traditional directed evolution methods [1][2]. Group 1: Technology Overview - The OTM system integrates three broadly host-compatible bacteriophage RNA polymerases and two deaminases, creating an efficient and modular protein evolution platform [2]. - The core principle involves RNA polymerase unwinding DNA to form single-stranded regions, allowing deaminases to edit exposed single-stranded DNA, achieving base mutations with a mutation efficiency increased by 1.5 million times compared to spontaneous mutations [2][3]. Group 2: Experimental Results - The research team successfully inserted bacteriophage promoters upstream and downstream of target genes, ensuring uniform distribution of mutations across target genes, overcoming previous biases in mutation distribution [3]. - The orthogonality experiments demonstrated that the OTM components could specifically recognize their respective promoters, avoiding cross-interference and enabling modular design [3]. Group 3: Applications and Future Prospects - The OTM system has shown great potential in applications, such as generating engineered strains with various colors by mutating fluorescent and pigment proteins, and creating unique shapes of engineered strains by targeting cytoskeletal and division-related proteins [3]. - In industrial applications, the system successfully evolved the σ70 global transcription regulator RpoD and lysine efflux protein LysE, enhancing L-arginine tolerance and transport capabilities [3][5]. - The technology has broad expansion potential, with possibilities to integrate other types of deaminases to enrich mutation diversity and explore compatibility in other non-model organisms [5].