PDF(Pubmed)
Abstract：
Synthetic biology holds immense promise to tackle key problems in resource use, environmental remediation, and human health care. However, comprehensive safety measures are lacking to employ engineered microorganisms in open-environment applications. Genetically encoded biocontainment systems may solve this issue. Here, we describe such a system based on conditional stability of essential proteins. We used a destabilizing domain degron stabilized by estradiol addition (ERdd). We ERdd-tagged 775 essential genes and screened for strains with estradiol dependent growth. Three genes, SPC110, DIS3 and RRP46, were found to be particularly suitable targets. Respective strains showed no growth defect in the presence of estradiol and strong growth inhibition in its absence. SPC110-ERdd offered the most stringent containment, with an escape frequency of <5×10-7. Removal of its C-terminal domain decreased the escape frequency further to <10-8. Being based on conditional protein stability, the presented approach is mechanistically orthogonal to previously reported genetic biocontainment systems.
摘要：
合成生物学在解决资源利用中的关键问题方面有着巨大的希望，环境修复,和人类保健。然而,缺乏在开放环境应用中采用工程微生物的综合安全措施。遗传编码的生物遏制系统可以解决这个问题。这里,我们描述了基于必需蛋白质的条件稳定性的系统。我们使用了通过添加雌二醇（ERdd）稳定的去稳定结构域degron。我们用ERdd标记了775个必需基因，并筛选了具有雌二醇依赖性生长的菌株。三个基因,发现SPC110、DIS3和RRP46是特别合适的靶标。在存在雌二醇的情况下，各个菌株均未显示出生长缺陷，而在不存在雌二醇的情况下，则显示出强的生长抑制作用。SPC110-ERdd提供了最严格的防护，逃逸频率<5×10-7。去除其C端结构域将逸出频率进一步降低至<10-8。基于条件蛋白质的稳定性，所提出的方法在机械上与先前报道的遗传生物保护系统正交。
