Engineering a Chemical Switch into the Light‐driven Proton Pump Proteorhodopsin by Cysteine Mutagenesis and Thiol Modification. Issue 31 (13th June 2016)

• Record Type: Journal Article
• Authors: Harder, Daniel; Hirschi, Stephan; Ucurum, Zöhre; Goers, Roland; Meier, Wolfgang; Müller, Daniel J.; Fotiadis, Dimitrios
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 31(2016)
• Page Start: 8846
• Page End: 8849
• Publication Date: 2016-06-13
• Subjects: light-driven proton pumps -- membrane proteins -- protein engineering -- proteorhodopsin -- synthetic biology; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201601537
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: For applications in synthetic biology, for example, the bottom‐up assembly of biomolecular nanofactories, modules of specific and controllable functionalities are essential. Of fundamental importance in such systems are energizing modules, which are able to establish an electrochemical gradient across a vesicular membrane as an energy source for powering other modules. Light‐driven proton pumps like proteorhodopsin (PR) are excellent candidates for efficient energy conversion. We have extended the versatility of PR by implementing an on/off switch based on reversible chemical modification of a site‐specifically introduced cysteine residue. The position of this cysteine residue in PR was identified by structure‐based cysteine mutagenesis combined with a proton‐pumping assay using E. coli cells overexpressing PR and PR proteoliposomes. The identified PR mutant represents the first light‐driven proton pump that can be chemically switched on/off depending on the requirements of the molecular system. Abstract : A chemical switch : Light‐driven proton pumps like proteorhodopsin (PR; gray structure with retinal cofactor in magenta) are excellent candidates for efficient energy conversion. The versatility of PR was extended by means of an on/off switch based on reversible chemical modification of a site‐specifically introduced cysteine residue. Chemical modification of this residue (green/yellow/red) blocks the channel and abolishes proton pumping under illumination.