title: Engineered Photoactivatable Genetic Switches Based on the Bacterium Phage T7 RNA Polymerase.
abstract: Genetic switches in which the activity of T7 RNA polymerase (RNAP) is directly regulated by external signals are obtained with an engineering strategy of splitting the protein into fragments and using regulatory domains to modulate their reconstitutions. Robust switchable systems with excellent dark-off/light-on properties are obtained with the light-activatable VVD domain and its variants as regulatory domains. For the best split position found, working switches exploit either the light-induced interactions between the VVD domains or allosteric effects. The split fragments show high modularity when they are combined with different regulatory domains such as those with chemically inducible interaction, enabling chemically controlled switches. To summarize, the T7 RNA polymerase-based switches are powerful tools to implement light-activated gene expression in different contexts. Moreover, results about the studied split positions and domain organizations may facilitate future engineering studies on this and on related proteins.
authors: Tiyun
authors: T
authors: Han
authors: Quan
authors: Q
authors: Chen
authors: Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei, Anhui 230031, China.
authors: Haiyan
authors: H
authors: Liu
mesh_terms: D017123:Bacteriophage T7 / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D003624:Darkness; D005818:Genetic Engineering; D008027:Light; D000072417:Protein Domains / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D014764:Viral Proteins; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases
keywords: allosteric control; genetic switch; light-regulated protein−protein interaction; modular domain organization; split T7 RNA polymerase