Laboratory of Microbial Metabolism and School of Life Science & Biotechnology, Shanghai Jiaotong University, 1954 Huashan Road, Shanghai 200030, China.
Modifications of the canonical structures of DNA and RNA play critical roles in cell physiology, DNA replication, transcription and translation in all organisms. We now report that bacterial dnd gene clusters incorporate sulfur into the DNA backbone as a sequence-selective, stereospecific phosphorothioate modification. To our knowledge, unlike any other DNA or RNA modification systems, DNA phosphorothioation by dnd gene clusters is the first physiological modification described on the DNA backbone.