@article{d88051b51a6c4db8a66aa84393b97898,
title = "Altered expression of a quality control protease in e. Coli reshapes the in vivo mutational landscape of a model enzyme",
abstract = "Protein mutational landscapes are shaped by the cellular environment, but key factors and their quantitative effects are often unknown. Here we show that Lon, a quality control protease naturally absent in common E. coli expression strains, drastically reshapes the mutational landscape of the metabolic enzyme dihydrofolate reductase (DHFR). Selection under conditions that resolve highly active mutants reveals that 23.3% of all single point mutations in DHFR are advantageous in the absence of Lon, but advantageous mutations are largely suppressed when Lon is reintroduced. Protein stability measurements demonstrate extensive activity-stability tradeoffs for the advantageous mutants and provide a mechanistic explanation for Lon{\textquoteright}s widespread impact. Our findings suggest possibilities for tuning mutational landscapes by modulating the cellular environment, with implications for protein design and combatting antibiotic resistance.",
author = "Samuel Thompson and Yang Zhang and Christine Ingle and Reynolds, {Kimberly A.} and Tanja Kortemme",
note = "Funding Information: The authors would like to thank Carol Gross, Melanie Silvis, and Byoung Mo Koo for discussion and for providing Lambda red plasmids; Rama Ranganathan and Victor Salinas for supplying parts and expertise for the construction of the turbidostat; Sharon Hammes-Shiffer and Phil Hanoian for providing QM/MM models of the hydride transfer step; Natasha Carli and Jim McGuire at the Gladstone Institute Genomics Core for performing NextSeq 500 sequencing runs with support from the James B Pendleton Charitable Trust; and Norma Neff, Anna Sellas, and Rene Sit for performing and aiding Miseq and NextSeq 500 sequencing runs at the Chan Zuckerberg Biohub. National Science Foundation- MCB 1615990 -Tanja Kortemme, Gordon and Betty Moore Foundation- GBMF4557 -Kimberly A Reynolds, National Science Foundation- Graduate Student Fellowship -Samuel Thompson, UCSF Chuan Lyu Chancellor{\textquoteright}s Fellowship- Graduate Student Fellowship -Samuel Thompson. Publisher Copyright: {\textcopyright} Thompson et al.",
year = "2020",
month = jul,
doi = "10.7554/eLife.53476",
language = "English (US)",
volume = "9",
pages = "1--47",
journal = "eLife",
issn = "2050-084X",
publisher = "eLife Sciences Publications",
}