Dietrich Lars E P, Teal Tracy K, Price-Whelan Alexa, Newman Dianne K
Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 01239, USA.
Science. 2008 Aug 29;321(5893):1203-6. doi: 10.1126/science.1160619.
It is thought that bacteria excrete redox-active pigments as antibiotics to inhibit competitors. In Pseudomonas aeruginosa, the endogenous antibiotic pyocyanin activates SoxR, a transcription factor conserved in Proteo- and Actinobacteria. In Escherichia coli, SoxR regulates the superoxide stress response. Bioinformatic analysis coupled with gene expression studies in P. aeruginosa and Streptomyces coelicolor revealed that the majority of SoxR regulons in bacteria lack the genes required for stress responses, despite the fact that many of these organisms still produce redox-active small molecules, which indicates that redox-active pigments play a role independent of oxidative stress. These compounds had profound effects on the structural organization of colony biofilms in both P. aeruginosa and S. coelicolor, which shows that "secondary metabolites" play important conserved roles in gene expression and development.
人们认为细菌会分泌具有氧化还原活性的色素作为抗生素来抑制竞争者。在铜绿假单胞菌中，内源性抗生素绿脓菌素会激活SoxR，这是一种在变形菌门和放线菌门中保守的转录因子。在大肠杆菌中，SoxR调节超氧化物应激反应。生物信息学分析以及在铜绿假单胞菌和天蓝色链霉菌中的基因表达研究表明，尽管许多这类生物体仍会产生具有氧化还原活性的小分子，但细菌中的大多数SoxR调控子缺乏应激反应所需的基因，这表明具有氧化还原活性的色素发挥着独立于氧化应激的作用。这些化合物对铜绿假单胞菌和天蓝色链霉菌的菌落生物膜结构组织都有深远影响，这表明“次生代谢产物”在基因表达和发育中发挥着重要的保守作用。
