Orthogonal translation with 5-cyanotryptophan as an infrared probe for local structural information, electrostatics, and hydrogen bonding.

Autor: von Freiherr Sass GJ; Technische Universität Berlin, Institut für Chemie/Biokatalyse, Berlin, Germany., Blain-Hartung M; Technische Universität Berlin, Institut für Chemie / Physikalische Chemie, Berlin, Germany., Baumann T; Technische Universität Berlin, Institut für Chemie/Biokatalyse, Berlin, Germany., Forest KT; Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA., Hildebrandt P; Technische Universität Berlin, Institut für Chemie / Physikalische Chemie, Berlin, Germany., Budisa N; Technische Universität Berlin, Institut für Chemie/Biokatalyse, Berlin, Germany.; Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada.
Jazyk: angličtina
Zdroj: Protein science : a publication of the Protein Society [Protein Sci] 2023 Jul; Vol. 32 (7), pp. e4705.
DOI: 10.1002/pro.4705
Abstrakt: Orthogonal translation is an efficient tool that provides many valuable spectral probes capable of covering different parts of the electromagnetic spectrum and thus enabling parameterization of various structural and dynamic phenomena in proteins. In this context, nitrile-containing tryptophan analogs are very useful probes to study local electrostatics and hydrogen bonding in both rigid and dynamic environments. Here, we report a semi-rational approach to engineer a tyrosyl-tRNA synthetase (TyrRS) variant of Methanocaldococcus jannaschii capable of incorporating 5-cyanotryptophan (5CNW) via orthogonal translation. We combined one round of the well-established positive selection system with saturation mutagenesis at preselected TyrRS positions, resulting in a novel 5CNW-specific enzyme that also exhibits high substrate tolerance to other aromatic noncanonical amino acids. We demonstrated the utility of our orthogonal pair by inserting 5CNW into the cyanobacteriochrome Slr1393g3, a bilin-binding photosensor of the phytochrome superfamily. The nitrile (CN) group of the inserted 5CNW provides non-invasive labeling in the local structural context while yielding information on local electrostatics and hydrogen bonding by IR spectroscopy. 5CNW is a versatile probe that can be used for both static and dynamic measurements.
(© 2023 The Authors. Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)
Databáze: MEDLINE
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