1
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Anderson NT, Xie JS, Chacko AN, Liu VL, Fan KC, Mukherjee A. Rational Design of a Circularly Permuted Flavin-Based Fluorescent Protein. Chembiochem 2024; 25:e202300814. [PMID: 38356332 PMCID: PMC11065581 DOI: 10.1002/cbic.202300814] [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: 12/01/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 02/16/2024]
Abstract
Flavin-based fluorescent proteins are oxygen-independent reporters that hold great promise for imaging anaerobic and hypoxic biological systems. In this study, we explored the feasibility of applying circular permutation, a valuable method for the creation of fluorescent sensors, to flavin-based fluorescent proteins. We used rational design and structural data to identify a suitable location for circular permutation in iLOV, a flavin-based reporter derived from A. thaliana. However, relocating the N- and C-termini to this position resulted in a significant reduction in fluorescence. This loss of fluorescence was reversible, however, by fusing dimerizing coiled coils at the new N- and C-termini to compensate for the increase in local chain entropy. Additionally, by inserting protease cleavage sites in circularly permuted iLOV, we developed two protease sensors and demonstrated their application in mammalian cells. In summary, our work establishes the first approach to engineer circularly permuted FbFPs optimized for high fluorescence and further showcases the utility of circularly permuted FbFPs to serve as a scaffold for sensor engineering.
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Affiliation(s)
| | - Jason S. Xie
- Department of Molecular, Cellular, and Developmental Biology
| | | | - Vannie L. Liu
- Department of Molecular, Cellular, and Developmental Biology
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2
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Hoffmann MD, Zdechlik AC, He Y, Nedrud D, Aslanidi G, Gordon W, Schmidt D. Multiparametric domain insertional profiling of adeno-associated virus VP1. Mol Ther Methods Clin Dev 2023; 31:101143. [PMID: 38027057 PMCID: PMC10661864 DOI: 10.1016/j.omtm.2023.101143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 10/21/2023] [Indexed: 12/01/2023]
Abstract
Several evolved properties of adeno-associated virus (AAV), such as broad tropism and immunogenicity in humans, are barriers to AAV-based gene therapy. Most efforts to re-engineer these properties have focused on variable regions near AAV's 3-fold protrusions and capsid protein termini. To comprehensively survey AAV capsids for engineerable hotspots, we determined multiple AAV fitness phenotypes upon insertion of six structured protein domains into the entire AAV-DJ capsid protein VP1. This is the largest and most comprehensive AAV domain insertion dataset to date. Our data revealed a surprising robustness of AAV capsids to accommodate large domain insertions. Insertion permissibility depended strongly on insertion position, domain type, and measured fitness phenotype, which clustered into contiguous structural units that we could link to distinct roles in AAV assembly, stability, and infectivity. We also identified engineerable hotspots of AAV that facilitate the covalent attachment of binding scaffolds, which may represent an alternative approach to re-direct AAV tropism.
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Affiliation(s)
- Mareike D. Hoffmann
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alina C. Zdechlik
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yungui He
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - David Nedrud
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Wendy Gordon
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Daniel Schmidt
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
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3
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Truong A, Myerscough D, Campbell I, Atkinson J, Silberg JJ. A cellular selection identifies elongated flavodoxins that support electron transfer to sulfite reductase. Protein Sci 2023; 32:e4746. [PMID: 37551563 PMCID: PMC10503412 DOI: 10.1002/pro.4746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 07/17/2023] [Accepted: 08/04/2023] [Indexed: 08/09/2023]
Abstract
Flavodoxins (Flds) mediate the flux of electrons between oxidoreductases in diverse metabolic pathways. To investigate whether Flds can support electron transfer to a sulfite reductase (SIR) that evolved to couple with a ferredoxin, we evaluated the ability of Flds to transfer electrons from a ferredoxin-NADP reductase (FNR) to a ferredoxin-dependent SIR using growth complementation of an Escherichia coli strain with a sulfur metabolism defect. We show that Flds from cyanobacteria complement this growth defect when coexpressed with an FNR and an SIR that evolved to couple with a plant ferredoxin. When we evaluated the effect of peptide insertion on Fld-mediated electron transfer, we observed a sensitivity to insertions within regions predicted to be proximal to the cofactor and partner binding sites, while a high insertion tolerance was detected within loops distal from the cofactor and within regions of helices and sheets that are proximal to those loops. Bioinformatic analysis showed that natural Fld sequence variability predicts a large fraction of the motifs that tolerate insertion of the octapeptide SGRPGSLS. These results represent the first evidence that Flds can support electron transfer to assimilatory SIRs, and they suggest that the pattern of insertion tolerance is influenced by interactions with oxidoreductase partners.
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Affiliation(s)
- Albert Truong
- Biochemistry and Cell Biology Graduate Program, Rice University, Houston, Texas, USA
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Dru Myerscough
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Ian Campbell
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Joshua Atkinson
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Jonathan J Silberg
- Department of Biosciences, Rice University, Houston, Texas, USA
- Department of Bioengineering, Rice University, Houston, Texas, USA
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas, USA
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4
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Hoffmann MD, Zdechlik AC, He Y, Nedrud D, Aslanidi G, Gordon W, Schmidt D. Multiparametric domain insertional profiling of Adeno-Associated Virus VP1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.19.537549. [PMID: 37131661 PMCID: PMC10153220 DOI: 10.1101/2023.04.19.537549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Evolved properties of Adeno-Associated Virus (AAV), such as broad tropism and immunogenicity in humans, are barriers to AAV-based gene therapy. Previous efforts to re-engineer these properties have focused on variable regions near AAV’s 3-fold protrusions and capsid protein termini. To comprehensively survey AAV capsids for engineerable hotspots, we determined multiple AAV fitness phenotypes upon insertion of large, structured protein domains into the entire AAV-DJ capsid protein VP1. This is the largest and most comprehensive AAV domain insertion dataset to date. Our data revealed a surprising robustness of AAV capsids to accommodate large domain insertions. There was strong positional, domain-type, and fitness phenotype dependence of insertion permissibility, which clustered into correlated structural units that we could link to distinct roles in AAV assembly, stability, and infectivity. We also identified new engineerable hotspots of AAV that facilitate the covalent attachment of binding scaffolds, which may represent an alternative approach to re-direct AAV tropism.
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5
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Fulk EM, Gao X, Lu LC, Redeker KR, Masiello CA, Silberg JJ. Nondestructive Chemical Sensing within Bulk Soil Using 1000 Biosensors Per Gram of Matrix. ACS Synth Biol 2022; 11:2372-2383. [PMID: 35715210 DOI: 10.1021/acssynbio.2c00083] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gene expression can be monitored in hard-to-image environmental materials using gas-reporting biosensors, but these outputs have only been applied in autoclaved matrices that are hydrated with rich medium. To better understand the compatibility of indicator gas reporting with environmental samples, we evaluated how matrix hydration affects the gas signal of an engineered microbe added to a sieved soil. A gas-reporting microbe presented a gas signal in a forest soil (Alfisol) when hydrated to an environmentally relevant osmotic pressure. When the gas signal was concentrated prior to analysis, a biosensor titer of 103 cells/gram of soil produced a significant signal when soil was supplemented with halides. A signal was also observed without halide amendment, but a higher cell titer (106 cells/gram of soil) was required. A sugar-regulated gas biosensor was able to report with a similar level of sensitivity when added to an unsterilized soil matrix, illustrating how gas concentration enables biosensing within a soil containing environmental microbes. These results establish conditions where engineered microbes can report on gene expression in living environmental matrices with decreased perturbation of the soil environment compared to previously reported approaches, using biosensor titers that are orders of magnitude lower than the number of cells typically observed in a gram of soil.
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Affiliation(s)
- Emily M Fulk
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, 6100 Main Street, MS-180, Houston, Texas 77005, United States
| | - Xiaodong Gao
- Department of Earth, Environmental and Planetary Sciences, Rice University, 6100 Main St, MS-126, Houston, Texas 77005, United States
| | - Li Chieh Lu
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Kelly R Redeker
- Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Caroline A Masiello
- Department of Earth, Environmental and Planetary Sciences, Rice University, 6100 Main St, MS-126, Houston, Texas 77005, United States.,Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Jonathan J Silberg
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States.,Department of Bioengineering, Rice University, 6100 Main Street, MS-142, Houston, Texas 77005, United States.,Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, MS-362, Houston, Texas 77005, United States
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6
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Campbell IJ, Atkinson JT, Carpenter MD, Myerscough D, Su L, Ajo-Franklin CM, Silberg JJ. Determinants of Multiheme Cytochrome Extracellular Electron Transfer Uncovered by Systematic Peptide Insertion. Biochemistry 2022; 61:1337-1350. [PMID: 35687533 DOI: 10.1021/acs.biochem.2c00148] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The multiheme cytochrome MtrA enables microbial respiration by transferring electrons across the outer membrane to extracellular electron acceptors. While structural studies have identified residues that mediate the binding of MtrA to hemes and to other cytochromes that facilitate extracellular electron transfer (EET), the relative importance of these interactions for EET is not known. To better understand EET, we evaluated how insertion of an octapeptide across all MtrA backbone locations affects Shewanella oneidensis MR-1 respiration on Fe(III). The EET efficiency was found to be inversely correlated with the proximity of the insertion to the heme prosthetic groups. Mutants with decreased EET efficiencies also arose from insertions in a subset of the regions that make residue-residue contacts with the porin MtrB, while all sites contacting the extracellular cytochrome MtrC presented high peptide insertion tolerance. MtrA variants having peptide insertions within the CXXCH motifs that coordinate heme cofactors retained some ability to support respiration on Fe(III), although these variants presented significantly decreased EET efficiencies. Furthermore, the fitness of cells expressing different MtrA variants under Fe(III) respiration conditions correlated with anode reduction. The peptide insertion profile, which represents the first comprehensive sequence-structure-function map for a multiheme cytochrome, implicates MtrA as a strategic protein engineering target for the regulation of EET.
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Affiliation(s)
- Ian J Campbell
- Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Joshua T Atkinson
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
| | - Matthew D Carpenter
- Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Dru Myerscough
- Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Lin Su
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Caroline M Ajo-Franklin
- Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States.,Department of Bioengineering, Rice University, 6100 Main Street, MS-142, Houston, Texas 77005, United States
| | - Jonathan J Silberg
- Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States.,Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, MS-362, Houston, Texas 77005, United States.,Department of Bioengineering, Rice University, 6100 Main Street, MS-142, Houston, Texas 77005, United States
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7
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Zhou K, Litfin T, Solayman M, Zhao H, Zhou Y, Zhan J. High-throughput split-protein profiling by combining transposon mutagenesis and regulated protein-protein interactions with deep sequencing. Int J Biol Macromol 2022; 203:543-552. [PMID: 35120933 DOI: 10.1016/j.ijbiomac.2022.01.173] [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: 08/02/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 11/05/2022]
Abstract
Splitting a protein at a position may lead to self- or assisted-complementary fragments depending on whether two resulting fragments can reconstitute to maintain the native function spontaneously or require assistance from two interacting molecules. Assisted complementary fragments with high contrast are an important tool for probing biological interactions. However, only a small number of assisted-complementary split-variants have been identified due to manual, labour-intensive optimization of a candidate gene. Here, we introduce a technique for high-throughput split-protein profiling (HiTS) that allows fast identification of self- and assisted complementary positions by transposon mutagenesis, a rapamycin-regulated FRB-FKBP protein interaction pair, and deep sequencing. We test this technique by profiling three antibiotic-resistant genes (fosfomycin-resistant gene, fosA3, erythromycin-resistant gene, ermB, and chloramphenicol-resistant gene, catI). Self- and assisted complementary fragments discovered by the high-throughput technique were subsequently confirmed by low-throughput testing of individual split positions. Thus, the HiTS technique provides a quicker alternative for discovering the proteins with suitable self- and assisted-complementary split positions when combining with a readout such as fluorescence, bioluminescence, cell survival, gene transcription or genome editing.
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Affiliation(s)
- Kai Zhou
- Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr Southport, QLD 4222, Australia; Institute for Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China
| | - Thomas Litfin
- Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr Southport, QLD 4222, Australia
| | - Md Solayman
- Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr Southport, QLD 4222, Australia
| | - Huijun Zhao
- Centre for Clean Environment and Energy, Griffith University, Gold Coast Campus, Queensland 4222, Australia
| | - Yaoqi Zhou
- Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr Southport, QLD 4222, Australia; Institute for Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China.
| | - Jian Zhan
- Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr Southport, QLD 4222, Australia; Institute for Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China.
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8
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Coyote-Maestas W, Nedrud D, He Y, Schmidt D. Determinants of trafficking, conduction, and disease within a K + channel revealed through multiparametric deep mutational scanning. eLife 2022; 11:76903. [PMID: 35639599 PMCID: PMC9273215 DOI: 10.7554/elife.76903] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 05/27/2022] [Indexed: 01/04/2023] Open
Abstract
A long-standing goal in protein science and clinical genetics is to develop quantitative models of sequence, structure, and function relationships to understand how mutations cause disease. Deep mutational scanning (DMS) is a promising strategy to map how amino acids contribute to protein structure and function and to advance clinical variant interpretation. Here, we introduce 7429 single-residue missense mutations into the inward rectifier K+ channel Kir2.1 and determine how this affects folding, assembly, and trafficking, as well as regulation by allosteric ligands and ion conduction. Our data provide high-resolution information on a cotranslationally folded biogenic unit, trafficking and quality control signals, and segregated roles of different structural elements in fold stability and function. We show that Kir2.1 surface trafficking mutants are underrepresented in variant effect databases, which has implications for clinical practice. By comparing fitness scores with expert-reviewed variant effects, we can predict the pathogenicity of 'variants of unknown significance' and disease mechanisms of known pathogenic mutations. Our study in Kir2.1 provides a blueprint for how multiparametric DMS can help us understand the mechanistic basis of genetic disorders and the structure-function relationships of proteins.
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Affiliation(s)
- Willow Coyote-Maestas
- Department of Biochemistry, Molecular Biology and Biophysics, University of MinnesotaMinneapolisUnited States
| | - David Nedrud
- Department of Biochemistry, Molecular Biology and Biophysics, University of MinnesotaMinneapolisUnited States
| | - Yungui He
- Department of Genetics, Cell Biology and Development, University of MinnesotaMinneapolisUnited States
| | - Daniel Schmidt
- Department of Genetics, Cell Biology and Development, University of MinnesotaMinneapolisUnited States
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9
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Coyote-Maestas W, Nedrud D, Suma A, He Y, Matreyek KA, Fowler DM, Carnevale V, Myers CL, Schmidt D. Probing ion channel functional architecture and domain recombination compatibility by massively parallel domain insertion profiling. Nat Commun 2021; 12:7114. [PMID: 34880224 PMCID: PMC8654947 DOI: 10.1038/s41467-021-27342-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 11/16/2021] [Indexed: 11/10/2022] Open
Abstract
Protein domains are the basic units of protein structure and function. Comparative analysis of genomes and proteomes showed that domain recombination is a main driver of multidomain protein functional diversification and some of the constraining genomic mechanisms are known. Much less is known about biophysical mechanisms that determine whether protein domains can be combined into viable protein folds. Here, we use massively parallel insertional mutagenesis to determine compatibility of over 300,000 domain recombination variants of the Inward Rectifier K+ channel Kir2.1 with channel surface expression. Our data suggest that genomic and biophysical mechanisms acted in concert to favor gain of large, structured domain at protein termini during ion channel evolution. We use machine learning to build a quantitative biophysical model of domain compatibility in Kir2.1 that allows us to derive rudimentary rules for designing domain insertion variants that fold and traffic to the cell surface. Positional Kir2.1 responses to motif insertion clusters into distinct groups that correspond to contiguous structural regions of the channel with distinct biophysical properties tuned towards providing either folding stability or gating transitions. This suggests that insertional profiling is a high-throughput method to annotate function of ion channel structural regions.
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Affiliation(s)
- Willow Coyote-Maestas
- grid.17635.360000000419368657Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455 USA
| | - David Nedrud
- grid.17635.360000000419368657Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455 USA
| | - Antonio Suma
- grid.264727.20000 0001 2248 3398Department of Chemistry, Temple University, Philadelphia, PA 19122 USA
| | - Yungui He
- grid.17635.360000000419368657Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455 USA
| | - Kenneth A. Matreyek
- grid.67105.350000 0001 2164 3847Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106 USA
| | - Douglas M. Fowler
- grid.34477.330000000122986657Department of Genome Sciences, University of Washington, Seattle, WA 98115 USA ,grid.34477.330000000122986657Department of Bioengineering, University of Washington, Seattle, WA 98115 USA
| | - Vincenzo Carnevale
- grid.264727.20000 0001 2248 3398Department of Chemistry, Temple University, Philadelphia, PA 19122 USA
| | - Chad L. Myers
- grid.17635.360000000419368657Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455 USA
| | - Daniel Schmidt
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN, 55455, USA.
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10
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Shams A, Higgins SA, Fellmann C, Laughlin TG, Oakes BL, Lew R, Kim S, Lukarska M, Arnold M, Staahl BT, Doudna JA, Savage DF. Comprehensive deletion landscape of CRISPR-Cas9 identifies minimal RNA-guided DNA-binding modules. Nat Commun 2021; 12:5664. [PMID: 34580310 PMCID: PMC8476515 DOI: 10.1038/s41467-021-25992-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 09/10/2021] [Indexed: 11/28/2022] Open
Abstract
Proteins evolve through the modular rearrangement of elements known as domains. Extant, multidomain proteins are hypothesized to be the result of domain accretion, but there has been limited experimental validation of this idea. Here, we introduce a technique for genetic minimization by iterative size-exclusion and recombination (MISER) for comprehensively making all possible deletions of a protein. Using MISER, we generate a deletion landscape for the CRISPR protein Cas9. We find that the catalytically-dead Streptococcus pyogenes Cas9 can tolerate large single deletions in the REC2, REC3, HNH, and RuvC domains, while still functioning in vitro and in vivo, and that these deletions can be stacked together to engineer minimal, DNA-binding effector proteins. In total, our results demonstrate that extant proteins retain significant modularity from the accretion process and, as genetic size is a major limitation for viral delivery systems, establish a general technique to improve genome editing and gene therapy-based therapeutics.
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Affiliation(s)
- Arik Shams
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Sean A Higgins
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, 94720, USA
- Scribe Therapeutics, Alameda, CA, 94501, USA
| | - Christof Fellmann
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Gladstone Institutes, San Francisco, CA, 94158, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Thomas G Laughlin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, 92093, USA
| | - Benjamin L Oakes
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, 94720, USA
- Scribe Therapeutics, Alameda, CA, 94501, USA
| | - Rachel Lew
- Gladstone Institutes, San Francisco, CA, 94158, USA
| | - Shin Kim
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Maria Lukarska
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Madeline Arnold
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Brett T Staahl
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, 94720, USA
- Scribe Therapeutics, Alameda, CA, 94501, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, 94720, USA
- Gladstone Institutes, San Francisco, CA, 94158, USA
- Graduate Group in Biophysics, University of California, Berkeley, Berkeley, CA, 94720, USA
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - David F Savage
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA.
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, 94720, USA.
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11
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Ho TYH, Shao A, Lu Z, Savilahti H, Menolascina F, Wang L, Dalchau N, Wang B. A systematic approach to inserting split inteins for Boolean logic gate engineering and basal activity reduction. Nat Commun 2021; 12:2200. [PMID: 33850130 PMCID: PMC8044194 DOI: 10.1038/s41467-021-22404-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/12/2021] [Indexed: 12/31/2022] Open
Abstract
Split inteins are powerful tools for seamless ligation of synthetic split proteins. Yet, their use remains limited because the already intricate split site identification problem is often complicated by the requirement of extein junction sequences. To address this, we augment a mini-Mu transposon-based screening approach and devise the intein-assisted bisection mapping (IBM) method. IBM robustly reveals clusters of split sites on five proteins, converting them into AND or NAND logic gates. We further show that the use of inteins expands functional sequence space for splitting a protein. We also demonstrate the utility of our approach over rational inference of split sites from secondary structure alignment of homologous proteins, and that basal activities of highly active proteins can be mitigated by splitting them. Our work offers a generalizable and systematic route towards creating split protein-intein fusions for synthetic biology.
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Affiliation(s)
- Trevor Y H Ho
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,Hangzhou Innovation Centre, Zhejiang University, Hangzhou, China.,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
| | - Alexander Shao
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,Microsoft Research, Cambridge, UK
| | - Zeyu Lu
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Filippo Menolascina
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh, UK
| | - Lei Wang
- School of Engineering, Westlake University, Hangzhou, China
| | | | - Baojun Wang
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK. .,Hangzhou Innovation Centre, Zhejiang University, Hangzhou, China. .,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China. .,ZJU-UoE Joint Research Centre for Engineering Biology, Zhejiang University, Haining, China.
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12
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Nazareno ES, Acharya B, Dumenyo CK. A mini-Tn5-derived transposon with reportable and selectable markers enables rapid generation and screening of insertional mutants in Gram-negative bacteria. Lett Appl Microbiol 2020; 72:283-291. [PMID: 33098689 DOI: 10.1111/lam.13423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/12/2020] [Accepted: 10/20/2020] [Indexed: 11/28/2022]
Abstract
We re-engineered a classic tool for mutagenesis and gene expression studies in Gram-negative bacteria. Our modified Tn5-based transposon contains multiple features that allow rapid selection for mutants, direct quantification of gene expression and straightforward cloning of the inactivated gene. The promoter-less gfp-km cassette provides selection and reporter assay depending on the activity of the promoter upstream of the transposon insertion site. The cat gene facilitates positive antibiotic selection for mutants, while the narrow R6Kγ replication origin forces transposition in recipient strains lacking the pir gene and enables cloning of the transposon flanked with the disrupted gene from the chromosome. The suicide vector pCKD100, a plasmid that could be delivered into recipient cells through biparental mating or electroporation, harbours the modified transposon. We used the transposon to mutagenize Pectobacterium versatile KD100, Pseudumonas coronafaciens PC27R and Escherichia coli 35150N. The fluorescence intensities of mutants expressing high GFP could be quantified and detected qualitatively. Transformation efficiency from conjugation ranged from 1600 to 1900 CFU per ml. We sequenced the upstream flanking regions, identified the putative truncated genes and demonstrated the restoration of the GFP phenotype through marker exchange. The mini-Tn5 transposon was also utilized to construct mutant a library of P. versatile for forward genetic screens.
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Affiliation(s)
- E S Nazareno
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, USA
| | - B Acharya
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, TN, USA
| | - C K Dumenyo
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, TN, USA
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Coyote-Maestas W, Nedrud D, Okorafor S, He Y, Schmidt D. Targeted insertional mutagenesis libraries for deep domain insertion profiling. Nucleic Acids Res 2020; 48:e11. [PMID: 31745561 PMCID: PMC6954442 DOI: 10.1093/nar/gkz1110] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/22/2019] [Accepted: 11/08/2019] [Indexed: 11/21/2022] Open
Abstract
Domain recombination is a key principle in protein evolution and protein engineering, but inserting a donor domain into every position of a target protein is not easily experimentally accessible. Most contemporary domain insertion profiling approaches rely on DNA transposons, which are constrained by sequence bias. Here, we establish Saturated Programmable Insertion Engineering (SPINE), an unbiased, comprehensive, and targeted domain insertion library generation technique using oligo library synthesis and multi-step Golden Gate cloning. Through benchmarking to MuA transposon-mediated library generation on four ion channel genes, we demonstrate that SPINE-generated libraries are enriched for in-frame insertions, have drastically reduced sequence bias as well as near-complete and highly-redundant coverage. Unlike transposon-mediated domain insertion that was severely biased and sparse for some genes, SPINE generated high-quality libraries for all genes tested. Using the Inward Rectifier K+ channel Kir2.1, we validate the practical utility of SPINE by constructing and comparing domain insertion permissibility maps. SPINE is the first technology to enable saturated domain insertion profiling. SPINE could help explore the relationship between domain insertions and protein function, and how this relationship is shaped by evolutionary forces and can be engineered for biomedical applications.
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Affiliation(s)
- Willow Coyote-Maestas
- Dept. of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - David Nedrud
- Dept. of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Steffan Okorafor
- Dept. of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yungui He
- Dept. of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Daniel Schmidt
- Dept. of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
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14
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Atkinson JT, Jones AM, Nanda V, Silberg JJ. Protein tolerance to random circular permutation correlates with thermostability and local energetics of residue-residue contacts. Protein Eng Des Sel 2019; 32:489-501. [PMID: 32626892 DOI: 10.1093/protein/gzaa012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 01/08/2023] Open
Abstract
Adenylate kinase (AK) orthologs with a range of thermostabilities were subjected to random circular permutation, and deep mutational scanning was used to evaluate where new protein termini were nondisruptive to activity. The fraction of circularly permuted variants that retained function in each library correlated with AK thermostability. In addition, analysis of the positional tolerance to new termini, which increase local conformational flexibility, showed that bonds were either functionally sensitive to cleavage across all homologs, differentially sensitive, or uniformly tolerant. The mobile AMP-binding domain, which displays the highest calculated contact energies, presented the greatest tolerance to new termini across all AKs. In contrast, retention of function in the lid and core domains was more dependent upon AK melting temperature. These results show that family permutation profiling identifies primary structure that has been selected by evolution for dynamics that are critical to activity within an enzyme family. These findings also illustrate how deep mutational scanning can be applied to protein homologs in parallel to differentiate how topology, stability, and local energetics govern mutational tolerance.
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Affiliation(s)
- Joshua T Atkinson
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, 6100 Main Street, MS-180, Houston, TX 77005, USA.,Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, TX 77005, USA
| | - Alicia M Jones
- Biochemistry and Cell Biology Graduate Program, Rice University, 6100 Main Street, MS-140, Houston, TX 77005, USA
| | - Vikas Nanda
- Center for Advanced Biotechnology and Medicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Jonathan J Silberg
- Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, TX 77005, USA.,Department of Bioengineering, Rice University, 6100 Main Street, MS-142, Houston, TX 77005, USA.,Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, MS-362, Houston, TX 77005, USA
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15
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Wu B, Atkinson JT, Kahanda D, Bennett GN, Silberg JJ. Combinatorial design of chemical‐dependent protein switches for controlling intracellular electron transfer. AIChE J 2019. [DOI: 10.1002/aic.16796] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Bingyan Wu
- Biochemistry & Cell Biology Graduate Program Rice University Houston Texas
- Department of Biosciences Rice University Houston Texas
| | - Joshua T. Atkinson
- Department of Biosciences Rice University Houston Texas
- Systems, Synthetic, & Physical Biology Graduate Program Rice University Houston Texas
| | | | - George N. Bennett
- Department of Biosciences Rice University Houston Texas
- Department of Chemical & Biomolecular Engineering Rice University Houston Texas
| | - Jonathan J. Silberg
- Department of Biosciences Rice University Houston Texas
- Department of Chemical & Biomolecular Engineering Rice University Houston Texas
- Department of Bioengineering Rice University Houston Texas
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16
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Atkinson JT, Wu B, Segatori L, Silberg JJ. Overcoming component limitations in synthetic biology through transposon-mediated protein engineering. Methods Enzymol 2019; 621:191-212. [DOI: 10.1016/bs.mie.2019.02.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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