Computational design of a red fluorophore ligase for site-specific protein labeling in living cells

Chemical fluorophores offer tremendous size and photophysical advantages over fluorescent proteins but are much more challenging to target to specific cellular proteins. Here, we used Rosetta-based computation to design a fluorophore ligase that accepts the red dye resorufin, starting from Escherich...

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Bibliographic Details
Main Authors: Baker, David, Ting, Alice Y., Liu, Daniel S., Nivon, Lucas G., Richter, Florian, Goldman, Peter J., Yao, Jennifer Z., Phipps, William S., Ye, Anne Z., Deerinck, Thomas J., Richardson, Douglas, Ellisman, Mark H., Drennan, Catherine L
Other Authors: Massachusetts Institute of Technology. Department of Biology
Format: Article
Language:en_US
Published: National Academy of Sciences (U.S.) 2015
Online Access:http://hdl.handle.net/1721.1/96304
https://orcid.org/0000-0001-5486-2755
https://orcid.org/0000-0002-8277-5226
Description
Summary:Chemical fluorophores offer tremendous size and photophysical advantages over fluorescent proteins but are much more challenging to target to specific cellular proteins. Here, we used Rosetta-based computation to design a fluorophore ligase that accepts the red dye resorufin, starting from Escherichia coli lipoic acid ligase. X-ray crystallography showed that the design closely matched the experimental structure. Resorufin ligase catalyzed the site-specific and covalent attachment of resorufin to various cellular proteins genetically fused to a 13-aa recognition peptide in multiple mammalian cell lines and in primary cultured neurons. We used resorufin ligase to perform superresolution imaging of the intermediate filament protein vimentin by stimulated emission depletion and electron microscopies. This work illustrates the power of Rosetta for major redesign of enzyme specificity and introduces a tool for minimally invasive, highly specific imaging of cellular proteins by both conventional and superresolution microscopies.