1
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Chamness LM, Kuntz CP, McKee AG, Penn WD, Hemmerich CM, Rusch DB, Woods H, Dyotima, Meiler J, Schlebach JP. Divergent folding-mediated epistasis among unstable membrane protein variants. eLife 2024; 12:RP92406. [PMID: 39078397 PMCID: PMC11288631 DOI: 10.7554/elife.92406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024] Open
Abstract
Many membrane proteins are prone to misfolding, which compromises their functional expression at the plasma membrane. This is particularly true for the mammalian gonadotropin-releasing hormone receptor GPCRs (GnRHR). We recently demonstrated that evolutionary GnRHR modifications appear to have coincided with adaptive changes in cotranslational folding efficiency. Though protein stability is known to shape evolution, it is unclear how cotranslational folding constraints modulate the synergistic, epistatic interactions between mutations. We therefore compared the pairwise interactions formed by mutations that disrupt the membrane topology (V276T) or tertiary structure (W107A) of GnRHR. Using deep mutational scanning, we evaluated how the plasma membrane expression of these variants is modified by hundreds of secondary mutations. An analysis of 251 mutants in three genetic backgrounds reveals that V276T and W107A form distinct epistatic interactions that depend on both the severity and the mechanism of destabilization. V276T forms predominantly negative epistatic interactions with destabilizing mutations in soluble loops. In contrast, W107A forms positive interactions with mutations in both loops and transmembrane domains that reflect the diminishing impacts of the destabilizing mutations in variants that are already unstable. These findings reveal how epistasis is remodeled by conformational defects in membrane proteins and in unstable proteins more generally.
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Affiliation(s)
- Laura M Chamness
- Department of Chemistry, Indiana UniversityBloomingtonUnited States
| | - Charles P Kuntz
- The James Tarpo Jr. and Margaret Tarpo Department of Chemistry, Purdue UniversityWest LafayetteUnited States
| | - Andrew G McKee
- Department of Chemistry, Indiana UniversityBloomingtonUnited States
| | - Wesley D Penn
- Department of Chemistry, Indiana UniversityBloomingtonUnited States
| | | | - Douglas B Rusch
- Center for Genomics and Bioinformatics, Indiana UniversityBloomingtonUnited States
| | - Hope Woods
- Department of Chemistry, Vanderbilt UniversityNashvilleUnited States
- Chemical and Physical Biology Program, Vanderbilt UniversityNashvilleUnited States
| | - Dyotima
- Department of Chemistry, Indiana UniversityBloomingtonUnited States
| | - Jens Meiler
- Department of Chemistry, Vanderbilt UniversityNashvilleUnited States
- Institute for Drug Discovery, Leipzig UniversityLeipzigGermany
| | - Jonathan P Schlebach
- The James Tarpo Jr. and Margaret Tarpo Department of Chemistry, Purdue UniversityWest LafayetteUnited States
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2
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Chisholm LO, Orlandi KN, Phillips SR, Shavlik MJ, Harms MJ. Ancestral Reconstruction and the Evolution of Protein Energy Landscapes. Annu Rev Biophys 2024; 53:127-146. [PMID: 38134334 PMCID: PMC11192866 DOI: 10.1146/annurev-biophys-030722-125440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
A protein's sequence determines its conformational energy landscape. This, in turn, determines the protein's function. Understanding the evolution of new protein functions therefore requires understanding how mutations alter the protein energy landscape. Ancestral sequence reconstruction (ASR) has proven a valuable tool for tackling this problem. In ASR, one phylogenetically infers the sequences of ancient proteins, allowing characterization of their properties. When coupled to biophysical, biochemical, and functional characterization, ASR can reveal how historical mutations altered the energy landscape of ancient proteins, allowing the evolution of enzyme activity, altered conformations, binding specificity, oligomerization, and many other protein features. In this article, we review how ASR studies have been used to dissect the evolution of energy landscapes. We also discuss ASR studies that reveal how energy landscapes have shaped protein evolution. Finally, we propose that thinking about evolution from the perspective of an energy landscape can improve how we approach and interpret ASR studies.
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Affiliation(s)
- Lauren O Chisholm
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon, USA;
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA
| | - Kona N Orlandi
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA
- Department of Biology, University of Oregon, Eugene, Oregon, USA
| | - Sophia R Phillips
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon, USA;
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA
| | - Michael J Shavlik
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA
- Department of Biology, University of Oregon, Eugene, Oregon, USA
| | - Michael J Harms
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon, USA;
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA
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3
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Reddy KD, Rasool B, Akher FB, Kutlešić N, Pant S, Boudker O. Evolutionary analysis reveals the origin of sodium coupling in glutamate transporters. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.03.569786. [PMID: 38106174 PMCID: PMC10723334 DOI: 10.1101/2023.12.03.569786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Secondary active membrane transporters harness the energy of ion gradients to concentrate their substrates. Homologous transporters evolved to couple transport to different ions in response to changing environments and needs. The bases of such diversification, and thus principles of ion coupling, are unexplored. Employing phylogenetics and ancestral protein reconstruction, we investigated sodium-coupled transport in prokaryotic glutamate transporters, a mechanism ubiquitous across life domains and critical to neurotransmitter recycling in humans. We found that the evolutionary transition from sodium-dependent to independent substrate binding to the transporter preceded changes in the coupling mechanism. Structural and functional experiments suggest that the transition entailed allosteric mutations, making sodium binding dispensable without affecting ion-binding sites. Allosteric tuning of transporters' energy landscapes might be a widespread route of their functional diversification.
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Affiliation(s)
- Krishna D. Reddy
- Dept. of Physiology & Biophysics, Weill Cornell Medical College, 1300 York Ave, New York, NY 10021, USA
| | - Burha Rasool
- Dept. of Physiology & Biophysics, Weill Cornell Medical College, 1300 York Ave, New York, NY 10021, USA
| | - Farideh Badichi Akher
- Dept. of Physiology & Biophysics, Weill Cornell Medical College, 1300 York Ave, New York, NY 10021, USA
| | - Nemanja Kutlešić
- Dept. of Physiology & Biophysics, Weill Cornell Medical College, 1300 York Ave, New York, NY 10021, USA
| | - Swati Pant
- Dept. of Biochemistry, Weill Cornell Medical College, 1300 York Ave, New York, NY 10021, USA
| | - Olga Boudker
- Dept. of Physiology & Biophysics, Weill Cornell Medical College, 1300 York Ave, New York, NY 10021, USA
- Howard Hughes Medical Institute, Weill Cornell Medical College, 1300 York Ave, New York, NY 10021, USA
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4
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Buda K, Miton CM, Tokuriki N. Pervasive epistasis exposes intramolecular networks in adaptive enzyme evolution. Nat Commun 2023; 14:8508. [PMID: 38129396 PMCID: PMC10739712 DOI: 10.1038/s41467-023-44333-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
Enzyme evolution is characterized by constant alterations of the intramolecular residue networks supporting their functions. The rewiring of these network interactions can give rise to epistasis. As mutations accumulate, the epistasis observed across diverse genotypes may appear idiosyncratic, that is, exhibit unique effects in different genetic backgrounds. Here, we unveil a quantitative picture of the prevalence and patterns of epistasis in enzyme evolution by analyzing 41 fitness landscapes generated from seven enzymes. We show that >94% of all mutational and epistatic effects appear highly idiosyncratic, which greatly distorted the functional prediction of the evolved enzymes. By examining seemingly idiosyncratic changes in epistasis along adaptive trajectories, we expose several instances of higher-order, intramolecular rewiring. Using complementary structural data, we outline putative molecular mechanisms explaining higher-order epistasis along two enzyme trajectories. Our work emphasizes the prevalence of epistasis and provides an approach to exploring this phenomenon through a molecular lens.
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Affiliation(s)
- Karol Buda
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Charlotte M Miton
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada.
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5
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Chakravarty D, Sreenivasan S, Swint-Kruse L, Porter LL. Identification of a covert evolutionary pathway between two protein folds. Nat Commun 2023; 14:3177. [PMID: 37264049 DOI: 10.1038/s41467-023-38519-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 05/03/2023] [Indexed: 06/03/2023] Open
Abstract
Although homologous protein sequences are expected to adopt similar structures, some amino acid substitutions can interconvert α-helices and β-sheets. Such fold switching may have occurred over evolutionary history, but supporting evidence has been limited by the: (1) abundance and diversity of sequenced genes, (2) quantity of experimentally determined protein structures, and (3) assumptions underlying the statistical methods used to infer homology. Here, we overcome these barriers by applying multiple statistical methods to a family of ~600,000 bacterial response regulator proteins. We find that their homologous DNA-binding subunits assume divergent structures: helix-turn-helix versus α-helix + β-sheet (winged helix). Phylogenetic analyses, ancestral sequence reconstruction, and AlphaFold2 models indicate that amino acid substitutions facilitated a switch from helix-turn-helix into winged helix. This structural transformation likely expanded DNA-binding specificity. Our approach uncovers an evolutionary pathway between two protein folds and provides a methodology to identify secondary structure switching in other protein families.
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Affiliation(s)
- Devlina Chakravarty
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA
| | - Shwetha Sreenivasan
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Liskin Swint-Kruse
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Lauren L Porter
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA.
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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6
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Wonderlick DR, Widom JR, Harms MJ. Disentangling contact and ensemble epistasis in a riboswitch. Biophys J 2023; 122:1600-1612. [PMID: 36710492 PMCID: PMC10183321 DOI: 10.1016/j.bpj.2023.01.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/09/2023] [Accepted: 01/24/2023] [Indexed: 01/29/2023] Open
Abstract
Mutations introduced into macromolecules often exhibit epistasis, where the effect of one mutation alters the effect of another. Knowing the mechanisms that lead to epistasis is important for understanding how macromolecules work and evolve, as well as for effective macromolecular engineering. Here, we investigate the interplay between "contact epistasis" (epistasis arising from physical interactions between mutated residues) and "ensemble epistasis" (epistasis that occurs when a mutation redistributes the conformational ensemble of a macromolecule, thus changing the effect of the second mutation). We argue that the two mechanisms can be distinguished in allosteric macromolecules by measuring epistasis at differing allosteric effector concentrations. Contact epistasis manifests as nonadditivity in the microscopic equilibrium constants describing the conformational ensemble. This epistatic effect is independent of allosteric effector concentration. Ensemble epistasis manifests as nonadditivity in thermodynamic observables-such as ligand binding-that are determined by the distribution of ensemble conformations. This epistatic effect strongly depends on allosteric effector concentration. Using this framework, we experimentally investigated the origins of epistasis in three pairwise mutant cycles introduced into the adenine riboswitch aptamer domain by measuring ligand binding as a function of allosteric effector concentration. We found evidence for both contact and ensemble epistasis in all cycles. Furthermore, we found that the two mechanisms of epistasis could interact with each other. For example, in one mutant cycle we observed 6 kcal/mol of contact epistasis in a microscopic equilibrium constant. In that same cycle, the maximum epistasis in ligand binding was only 1.5 kcal/mol: shifts in the ensemble masked the contribution of contact epistasis. Finally, our work yields simple heuristics for identifying contact and ensemble epistasis based on measurements of a biochemical observable as a function of allosteric effector concentration.
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Affiliation(s)
- Daria R Wonderlick
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon
| | - Julia R Widom
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon; Institute for Molecular Biology, University of Oregon, Eugene, Oregon; Oregon Center for Optical, Molecular, & Quantum Science, University of Oregon, Eugene, Oregon
| | - Michael J Harms
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon; Institute for Molecular Biology, University of Oregon, Eugene, Oregon.
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7
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Samanta R, Matysiak S. Decoupling epistasis mechanisms in biomacromolecules. Biophys J 2023; 122:1574-1576. [PMID: 37080208 PMCID: PMC10183367 DOI: 10.1016/j.bpj.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/26/2023] [Accepted: 04/03/2023] [Indexed: 04/22/2023] Open
Affiliation(s)
- Riya Samanta
- Biophysics Graduate Program, The University of Maryland, College Park, College Park, Maryland
| | - Silvina Matysiak
- Fischell Department of Bioengineering, The University of Maryland, College Park, College Park, Maryland.
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8
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Densi A, Iyer RS, Bhat PJ. Synonymous and Nonsynonymous Substitutions in Dictyostelium discoideum Ammonium Transporter amtA Are Necessary for Functional Complementation in Saccharomyces cerevisiae. Microbiol Spectr 2023; 11:e0384722. [PMID: 36840598 PMCID: PMC10100761 DOI: 10.1128/spectrum.03847-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/24/2023] [Indexed: 02/24/2023] Open
Abstract
Ammonium transporters are present in all three domains of life. They have undergone extensive horizontal gene transfer (HGT), gene duplication, and functional diversification and therefore offer an excellent paradigm to study protein evolution. We attempted to complement a mep1Δmep2Δmep3Δ strain of Saccharomyces cerevisiae (triple-deletion strain), which otherwise cannot grow on ammonium as a sole nitrogen source at concentrations of <3 mM, with amtA of Dictyostelium discoideum, an orthologue of S. cerevisiae MEP2. We observed that amtA did not complement the triple-deletion strain of S. cerevisiae for growth on low-ammonium medium. We isolated two mutant derivatives of amtA (amtA M1 and amtA M2) from a PCR-generated mutant plasmid library that complemented the triple-deletion strain of S. cerevisiae. amtA M1 bears three nonsynonymous and two synonymous substitutions, which are necessary for its functionality. amtA M2 bears two nonsynonymous substitutions and one synonymous substitution, all of which are necessary for functionality. Interestingly, AmtA M1 transports ammonium but does not confer methylamine toxicity, while AmtA M2 transports ammonium and confers methylamine toxicity, demonstrating functional diversification. Preliminary biochemical analyses indicated that the mutants differ in their conformations as well as their mechanisms of ammonium transport. These intriguing results clearly point out that protein evolution cannot be fathomed by studying nonsynonymous and synonymous substitutions in isolation. The above-described observations have significant implications for various facets of biological processes and are discussed in detail. IMPORTANCE Functional diversification following gene duplication is one of the major driving forces of protein evolution. While the role of nonsynonymous substitutions in the functional diversification of proteins is well recognized, knowledge of the role of synonymous substitutions in protein evolution is in its infancy. Using functional complementation, we isolated two functional alleles of the D. discoideum ammonium transporter gene (amtA), which otherwise does not function in S. cerevisiae as an ammonium transporters. One of them is an ammonium transporter, while the other is an ammonium transporter that also confers methylammonium (ammonium analogue) toxicity, suggesting functional diversification. Surprisingly, both alleles require a combination of synonymous and nonsynonymous substitutions for their functionality. These results bring out a hitherto-unknown pathway of protein evolution and pave the way for not only understanding protein evolution but also interpreting single nucleotide polymorphisms (SNPs).
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Affiliation(s)
- Asha Densi
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Revathi S. Iyer
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Paike Jayadeva Bhat
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
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9
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Harman JL, Reardon PN, Costello SM, Warren GD, Phillips SR, Connor PJ, Marqusee S, Harms MJ. Evolution avoids a pathological stabilizing interaction in the immune protein S100A9. Proc Natl Acad Sci U S A 2022; 119:e2208029119. [PMID: 36194634 PMCID: PMC9565474 DOI: 10.1073/pnas.2208029119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/07/2022] [Indexed: 01/03/2023] Open
Abstract
Stability constrains evolution. While much is known about constraints on destabilizing mutations, less is known about the constraints on stabilizing mutations. We recently identified a mutation in the innate immune protein S100A9 that provides insight into such constraints. When introduced into human S100A9, M63F simultaneously increases the stability of the protein and disrupts its natural ability to activate Toll-like receptor 4. Using chemical denaturation, we found that M63F stabilizes a calcium-bound conformation of hS100A9. We then used NMR to solve the structure of the mutant protein, revealing that the mutation distorts the hydrophobic binding surface of hS100A9, explaining its deleterious effect on function. Hydrogen-deuterium exchange (HDX) experiments revealed stabilization of the region around M63F in the structure, notably Phe37. In the structure of the M63F mutant, the Phe37 and Phe63 sidechains are in contact, plausibly forming an edge-face π-stack. Mutating Phe37 to Leu abolished the stabilizing effect of M63F as probed by both chemical denaturation and HDX. It also restored the biological activity of S100A9 disrupted by M63F. These findings reveal that Phe63 creates a molecular staple with Phe37 that stabilizes a nonfunctional conformation of the protein, thus disrupting function. Using a bioinformatic analysis, we found that S100A9 proteins from different organisms rarely have Phe at both positions 37 and 63, suggesting that avoiding a pathological stabilizing interaction indeed constrains S100A9 evolution. This work highlights an important evolutionary constraint on stabilizing mutations, namely, that they must avoid inappropriately stabilizing nonfunctional protein conformations.
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Affiliation(s)
- Joseph L Harman
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Patrick N Reardon
- College of Science, NMR Facility, Oregon State University, Corvallis, OR 97331
| | - Shawn M Costello
- Biophysics Graduate Program, University of California, Berkeley, Berkeley, CA 94720
| | - Gus D Warren
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Sophia R Phillips
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Patrick J Connor
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Susan Marqusee
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720
| | - Michael J Harms
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
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10
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Azbukina N, Zharikova A, Ramensky V. Intragenic compensation through the lens of deep mutational scanning. Biophys Rev 2022; 14:1161-1182. [PMID: 36345285 PMCID: PMC9636336 DOI: 10.1007/s12551-022-01005-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 09/26/2022] [Indexed: 12/20/2022] Open
Abstract
A significant fraction of mutations in proteins are deleterious and result in adverse consequences for protein function, stability, or interaction with other molecules. Intragenic compensation is a specific case of positive epistasis when a neutral missense mutation cancels effect of a deleterious mutation in the same protein. Permissive compensatory mutations facilitate protein evolution, since without them all sequences would be extremely conserved. Understanding compensatory mechanisms is an important scientific challenge at the intersection of protein biophysics and evolution. In human genetics, intragenic compensatory interactions are important since they may result in variable penetrance of pathogenic mutations or fixation of pathogenic human alleles in orthologous proteins from related species. The latter phenomenon complicates computational and clinical inference of an allele's pathogenicity. Deep mutational scanning is a relatively new technique that enables experimental studies of functional effects of thousands of mutations in proteins. We review the important aspects of the field and discuss existing limitations of current datasets. We reviewed ten published DMS datasets with quantified functional effects of single and double mutations and described rates and patterns of intragenic compensation in eight of them. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-022-01005-w.
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Affiliation(s)
- Nadezhda Azbukina
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 1-73, Leninskie Gory, 119991 Moscow, Russia
| | - Anastasia Zharikova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 1-73, Leninskie Gory, 119991 Moscow, Russia
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, Bld.3, 101000 Moscow, Russia
| | - Vasily Ramensky
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 1-73, Leninskie Gory, 119991 Moscow, Russia
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, Bld.3, 101000 Moscow, Russia
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11
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Park Y, Metzger BPH, Thornton JW. Epistatic drift causes gradual decay of predictability in protein evolution. Science 2022; 376:823-830. [PMID: 35587978 DOI: 10.1126/science.abn6895] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Epistatic interactions can make the outcomes of evolution unpredictable, but no comprehensive data are available on the extent and temporal dynamics of changes in the effects of mutations as protein sequences evolve. Here, we use phylogenetic deep mutational scanning to measure the functional effect of every possible amino acid mutation in a series of ancestral and extant steroid receptor DNA binding domains. Across 700 million years of evolution, epistatic interactions caused the effects of most mutations to become decorrelated from their initial effects and their windows of evolutionary accessibility to open and close transiently. Most effects changed gradually and without bias at rates that were largely constant across time, indicating a neutral process caused by many weak epistatic interactions. Our findings show that protein sequences drift inexorably into contingency and unpredictability, but that the process is statistically predictable, given sufficient phylogenetic and experimental data.
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Affiliation(s)
- Yeonwoo Park
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
| | - Brian P H Metzger
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - Joseph W Thornton
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA.,Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA.,Department of Human Genetics, University of Chicago, Chicago, IL, USA
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12
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Mokhtari DA, Appel MJ, Fordyce PM, Herschlag D. High throughput and quantitative enzymology in the genomic era. Curr Opin Struct Biol 2021; 71:259-273. [PMID: 34592682 PMCID: PMC8648990 DOI: 10.1016/j.sbi.2021.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 07/23/2021] [Indexed: 12/28/2022]
Abstract
Accurate predictions from models based on physical principles are the ultimate metric of our biophysical understanding. Although there has been stunning progress toward structure prediction, quantitative prediction of enzyme function has remained challenging. Realizing this goal will require large numbers of quantitative measurements of rate and binding constants and the use of these ground-truth data sets to guide the development and testing of these quantitative models. Ground truth data more closely linked to the underlying physical forces are also desired. Here, we describe technological advances that enable both types of ground truth measurements. These advances allow classic models to be tested, provide novel mechanistic insights, and place us on the path toward a predictive understanding of enzyme structure and function.
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Affiliation(s)
- D A Mokhtari
- Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA
| | - M J Appel
- Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA
| | - P M Fordyce
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA, 94305, USA; Department of Genetics, Stanford University, Stanford, CA, 94305, USA; Chan Zuckerberg Biohub San Francisco, CA, 94110, USA.
| | - D Herschlag
- Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA; Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA, 94305, USA.
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