Deconstruction of the Ras switching cycle through saturation mutagenesis
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elife-27810-v2.pdf
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8.74 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Bandaru, Pradeep
Shah, Neel H
Bhattacharyya, Moitrayee
Barton, John P
Kondo, Yasushi
Cofsky, Joshua C
Gee, Christine L
Chakraborty, Arup K
Kortemme, Tanja
Ranganathan, Rama
Date Issued
July 2017
Journal
eLife
Publisher
eLife Sciences Publications, Ltd
Citation
Bandaru, Pradeep et al. “Deconstruction of the Ras Switching Cycle through Saturation Mutagenesis.” eLife 2017, 6 (July 2017): e27810 © Bandaru et al
Version
Final published version
Abstract
Ras proteins are highly conserved signaling molecules that exhibit regulated, nucleotide-dependent switching between active and inactive states. The high conservation of Ras requires mechanistic explanation, especially given the general mutational tolerance of proteins. Here, we use deep mutational scanning, biochemical analysis and molecular simulations to understand constraints on Ras sequence. Ras exhibits global sensitivity to mutation when regulated by a GTPase activating protein and a nucleotide exchange factor. Removing the regulators shifts the distribution of mutational effects to be largely neutral, and reveals hotspots of activating mutations in residues that restrain Ras dynamics and promote the inactive state. Evolutionary analysis, combined with structural and mutational data, argue that Ras has co-evolved with its regulators in the vertebrate lineage. Overall, our results show that sequence conservation in Ras depends strongly on the biochemical network in which it operates, providing a framework for understanding the origin of global selection pressures on proteins.
MIT Department
Institute for Medical Engineering and Science
Massachusetts Institute of Technology. Department of Biological Engineering
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Chemistry
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.7554/ELIFE.27810
