Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA 94608, USA.
Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
J Biol Eng. 2011 Sep 20;5:12. doi: 10.1186/1754-1611-5-12.
As engineered biological systems become more complex, it is increasingly common to express multiple operons from different plasmids and inducible expression systems within a single host cell. Optimizing such systems often requires screening combinations of origins of replication, expression systems, and antibiotic markers. This procedure is hampered by a lack of quantitative data on how these components behave when more than one origin of replication or expression system are used simultaneously. Additionally, this process can be time consuming as it often requires the creation of new vectors or cloning into existing but disparate vectors.
Here, we report the development and characterization of a library of expression vectors compatible with the BglBrick standard (BBF RFC 21). We have designed and constructed 96 BglBrick-compatible plasmids with a combination of replication origins, antibiotic resistance genes, and inducible promoters. These plasmids were characterized over a range of inducer concentrations, in the presence of non-cognate inducer molecules, and with several growth media, and their characteristics were documented in a standard format datasheet. A three plasmid system was used to investigate the impact of multiple origins of replication on plasmid copy number.
The standardized collection of vectors presented here allows the user to rapidly construct and test the expression of genes with various combinations of promoter strength, inducible expression system, copy number, and antibiotic resistance. The quantitative datasheets created for these vectors will increase the predictability of gene expression, especially when multiple plasmids and inducers are utilized.
随着工程生物系统变得越来越复杂,在单个宿主细胞中表达来自不同质粒和诱导表达系统的多个操纵子变得越来越常见。优化此类系统通常需要筛选复制起点、表达系统和抗生素标记物的组合。由于缺乏关于当同时使用多个复制起点或表达系统时这些组件如何表现的定量数据,因此该过程受到阻碍。此外,由于通常需要创建新的载体或克隆到现有但不同的载体中,因此该过程可能会很耗时。
在这里,我们报告了与 BglBrick 标准 (BBF RFC 21) 兼容的表达载体文库的开发和特性。我们设计并构建了 96 个带有复制起点、抗生素抗性基因和诱导启动子组合的 BglBrick 兼容质粒。这些质粒在一系列诱导剂浓度下、存在非同源诱导剂分子的情况下以及几种生长培养基中进行了表征,并以标准格式数据表记录了它们的特性。使用三质粒系统研究了多个复制起点对质粒拷贝数的影响。
这里呈现的标准化载体集合允许用户快速构建和测试具有各种启动子强度、诱导表达系统、拷贝数和抗生素抗性组合的基因的表达。为这些载体创建的定量数据表将提高基因表达的可预测性,尤其是在使用多个质粒和诱导剂时。