Romano, EdoardoBaumschlager, ArminAkmeriç, Emir BoraPalanisamy, NavaneethanHoumani, MoustafaSchmidt, GregorÖztürk, Mehmet AliErnst, LeonardKhammash, MustafaDi Ventura, Barbara2025-06-162025-06-162021-04-26Romano, E., Baumschlager, A., Akmeric, E. B., Palanisamy, N., Houmani, M., Schmidt, G., Öztürk, M. A., Ernst, L., Khammash, M., & Di Ventura, B. (2021). Engineering AraC to make it responsive to light instead of arabinose. Nature chemical biology, 17(7), 817-827.1552-445010.1038/s41589-021-00787-6http://hdl.handle.net/10034/629466This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1038/s41589-021-00787-6.The l-arabinose-responsive AraC and its cognate PBAD promoter underlie one of the most often used chemically inducible prokaryotic gene expression systems in microbiology and synthetic biology. Here, we change the sensing capability of AraC from l-arabinose to blue light, making its dimerization and the resulting PBAD activation light-inducible. We engineer an entire family of blue light-inducible AraC dimers in Escherichia coli (BLADE) to control gene expression in space and time. We show that BLADE can be used with pre-existing l-arabinose-responsive plasmids and strains, enabling optogenetic experiments without the need to clone. Furthermore, we apply BLADE to control, with light, the catabolism of l-arabinose, thus externally steering bacterial growth with a simple transformation step. Our work establishes BLADE as a highly practical and effective optogenetic tool with plug-and-play functionality—features that we hope will accelerate the broader adoption of optogenetics and the realization of its vast potential in microbiology, synthetic biology and biotechnology.Print-ElectronicenL-arabinose-responsive AraCEscherichia coli (BLADE)Gene expressionMicrobiologySynthetic biologyBiotechnologyAraC Transcription FactorArabinoseEscherichia coliEscherichia coli ProteinsGenetic EngineeringLightAraC Transcription FactorArabinoseEscherichia coliEscherichia coli ProteinsGenetic EngineeringLightEscherichia coliArabinoseEscherichia coli ProteinsGenetic EngineeringLightAraC Transcription FactorArticle1552-4469Nature Chemical Biology2025-06-1317