Zhou Jie, Zhang Haifeng, Meng Hengkai, Zhu Yan, Bao Guanhui, Zhang Yanping, Li Yin, Ma Yanhe
CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
1] CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China [2] University of Chinese Academy of Sciences, Beijing, China.
Sci Rep. 2014 Mar 28;4:4500. doi: 10.1038/srep04500.
Cyanobacteria are oxygenic photosynthetic prokaryotes that play important roles in the global carbon cycle. Recently, engineered cyanobacteria capable of producing various small molecules from CO2 have been developed. However, cyanobacteria are seldom considered as factories for producing proteins, mainly because of the lack of efficient strong promoters. Here, we report the discovery and verification of a super-strong promoter P(cpc560), which contains two predicted promoters and 14 predicted transcription factor binding sites (TFBSs). Using P(cpc560), functional proteins were produced at a level of up to 15% of total soluble protein in the cyanobacterium Synechocystis sp. 6803, a level comparable to that produced in Escherichia coli. We demonstrated that the presence of multiple TFBSs in P(cpc560) is crucial for its promoter strength. Genetically transformable cyanobacteria neither have endotoxins nor form inclusion bodies; therefore, P(cpc560) opens the possibility to use cyanobacteria as alternative hosts for producing heterogeneous proteins from CO2 and inorganic nutrients.
蓝藻是进行产氧光合作用的原核生物，在全球碳循环中发挥着重要作用。最近，已经开发出了能够从二氧化碳中产生各种小分子的工程蓝藻。然而，蓝藻很少被视为生产蛋白质的工厂，主要是因为缺乏高效的强启动子。在此，我们报告了一种超强启动子P(cpc560)的发现与验证，它包含两个预测的启动子和14个预测的转录因子结合位点（TFBSs）。使用P(cpc560)，在蓝藻集胞藻6803中，功能性蛋白质的产量高达总可溶性蛋白的15%，这一水平与在大肠杆菌中产生的水平相当。我们证明，P(cpc560)中多个TFBSs的存在对其启动子强度至关重要。可遗传转化的蓝藻既没有内毒素也不会形成包涵体；因此，P(cpc560)开启了将蓝藻用作从二氧化碳和无机营养物中生产异源蛋白质的替代宿主的可能性。
