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. 2019 Aug 11;12(9):1721–1742. doi: 10.1111/eva.12846

Figure 4.

Figure 4

A sample of experimentally characterized elasticity functions, all of a saturating concave form. (a) Function: expression level—growth rate; protein: chaperone; organism: Saccharomyces cerevisiae. [Reprinted from (Jiang et al., 2013), licensed under CC BY 4.0]. (b) Function: enzymatic performance (k cat/K m)—fitness, under 2 different coenzymes; protein: oxidoreductase (amino‐acid biosynthesis); organism: Escherichia coli. [From Science, 310(5,747), 501, The biochemical architecture of an ancient adaptive landscape (Lunzer et al.., 2005). Reprinted with permission from AAAS]. (c) Left‐right, top‐bottom. Functions: enzymatic activity—metabolic flux (first 4), gene dose—growth rate, enzymatic efficiency (V max/K m)—metabolic flux, gene dose—DNA repair rate, enzymatic efficiency—metabolic flux; proteins: lyase, transferase, ligase, aminotransferase (all from same amino‐acid biosynthesis pathway), carboxylase (nucleotide biosynthesis), oxidoreductase (melanin biosynthesis), unknown gene defective in a xeroderma pigmentosum patient (nucleotide repair), oxidoreductase (ethanol oxidation); organism: Neurospora crassa (first 4), Saccharomyces cerevisiae, Mus musculus, Homo sapiens, Drosophila melanogaster. [Republished with permission of Genetics Society of America, from Genetics, 97(3–4), 642, The molecular basis of dominance (Kacser & Burns, 1981); permission conveyed through Copyright Clearance Center, Inc.]. (d) Function: expression level—growth rate; protein: oxidoreductase (cofactor biosynthesis); organism: Escherichia coli. [Reprinted from Molecular Cell, 49(1), 137, Protein quality control acts on folding intermediates to shape the effects of mutations on organismal fitness (Bershtein et al., 2013). Copyright (2013), with permission from Elsevier]. (e) Function: enzymatic activity—fitness; proteins: sugar:proton symporter and hydrolase (sugar catabolism); organism: Escherichia coli. [Republished with permission of Genetics Society of America, from Genetics, 115(1), 29, Metabolic flux and fitness (Dykhuizen et al., 1987); permission conveyed through Copyright Clearance Center, Inc.]