Directed evolution of extradiol dioxygenase by a novel in vivo DNA shuffling

Gene ◽  
2006 ◽  
Vol 368 ◽  
pp. 126-137 ◽  
Author(s):  
Shujing Xu ◽  
Jiansong Ju ◽  
Haruo Misono ◽  
Kouhei Ohnishi
Keyword(s):  
Directed Evolution ◽  
Dna Shuffling ◽  
Extradiol Dioxygenase

scholarly journals Novaferon, a novel recombinant protein produced by DNA-shuffling of IFN-α, shows antitumor effect in vitro and in vivo

2014 ◽  
Vol 14 (1) ◽  
pp. 8 ◽  
Author(s):  
Meng Li ◽  
Chunming Rao ◽  
Dening Pei ◽  
Lan Wang ◽  
Yonghong Li ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Antitumor Effect ◽  
Dna Shuffling

scholarly journals Click-chemistry enabled directed evolution of glycosynthases for bespoke glycans synthesis

2020 ◽  
Author(s):  
Ayushi Agrawal ◽  
Chandra Kanth Bandi ◽  
Tucker Burgin ◽  
Youngwoo Woo ◽  
Heather B. Mayes ◽  
...  
Keyword(s):  
Single Cell ◽  
Click Chemistry ◽  
Directed Evolution ◽  
Cell Sorting ◽  
Screening Methods ◽  
Carbohydrate Active Enzymes ◽  
E Coli ◽  
Highly Sensitive ◽  
Increased Activity

AbstractEngineering of carbohydrate-active enzymes like glycosynthases for chemoenzymatic synthesis of bespoke oligosaccharides has been limited by the lack of suitable directed evolution based protein engineering methods. Currently there are no ultrahigh-throughput screening methods available for rapid and highly sensitive single cell-based screening of evolved glycosynthase enzymes employing azido sugars as substrates. Here, we report a fluorescence-based approach employing click-chemistry for the selective detection of glycosyl azides (versus free inorganic azides) that facilitated ultrahigh-throughput in-vivo single cell-based assay of glycosynthase activity. This discovery has led to the development of a directed evolution methodology for screening and sorting glycosynthase mutants for synthesis of desired fucosylated oligosaccharides. Our screening technique facilitated rapid fluorescence activated cell sorting of a large library of glycosynthase variants (>106 mutants) expressed in E. coli to identify several novel mutants with increased activity for β-fucosyl-azide activated donor sugars towards desired acceptor sugars, demonstrating the broader applicability of this methodology.

scholarly journals Directed Evolution of an Influenza Reporter Virus To Restore Replication and Virulence and Enhance Noninvasive Bioluminescence Imaging in Mice

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Hui Cai ◽  
Meisui Liu ◽  
Charles J. Russell
Keyword(s):  
Gene Expression ◽  
Influenza Virus ◽  
Virus Infection ◽  
Directed Evolution ◽  
Influenza Virus Infection ◽  
Foreign Gene ◽  
Reporter Virus ◽  
Wild Type ◽  
Bioluminescence Signal

ABSTRACTReporter viruses provide a powerful tool to study infection, yet incorporating a nonessential gene often results in virus attenuation and genetic instability. Here, we used directed evolution of a luciferase-expressing pandemic H1N1 (pH1N1) 2009 influenza A virus in mice to restore replication kinetics and virulence, increase the bioluminescence signal, and maintain reporter gene expression. An unadapted pH1N1 virus withNanoLuc luciferaseinserted into the 5′ end of the PA gene segment grew to titers 10-fold less than those of the wild type in MDCK cells and in DBA/2 mice and was less virulent. For 12 rounds, we propagated DBA/2 lung samples with the highest bioluminescence-to-titer ratios. Every three rounds, we comparedin vivoreplication, weight loss, mortality, and bioluminescence. Mouse-adapted virus after 9 rounds (MA-9) had the highest relative bioluminescence signal and had wild-type-like fitness and virulence in DBA/2 mice. Using reverse genetics, we discovered fitness was restored in virus rPB2-MA9/PA-D479N by a combination of PA-D479N and PB2-E158G amino acid mutations andPB2noncoding mutations C1161T and C1977T. rPB2-MA9/PA-D479N has increased mRNA transcription, which helps restore wild-type-like phenotypes in DBA/2 and BALB/c mice. Overall, the results demonstrate that directed evolution that maximizes foreign-gene expression while maintaining genetic stability is an effective method to restore wild-type-likein vivofitness of a reporter virus. Virus rPB2-MA9/PA-D479N is expected to be a useful tool for noninvasive imaging of pH1N1 influenza virus infection and clearance while analyzing virus-host interactions and developing new therapeutics and vaccines.IMPORTANCEInfluenza viruses contribute to 290,000 to 650,000 deaths globally each year. Infection is studied in mice to learn how the virus causes sickness and to develop new drugs and vaccines. During experiments, scientists have needed to euthanize groups of mice at different times to measure the amount of infectious virus in mouse tissues. By inserting a foreign gene that causes infected cells to light up, scientists could see infection spread in living mice. Unfortunately, adding an extra gene not needed by the virus slowed it down and made it weaker. Here, we used a new strategy to restore the fitness and lethality of an influenza reporter virus; we adapted it to mouse lungs and selected for variants that had the greatest light signal. The adapted virus can be used to study influenza virus infection, immunology, and disease in living mice. The strategy can also be used to adapt other viruses.

scholarly journals Directed Evolution of a Homodimeric Laccase from Cerrena unicolor BBP6 by Random Mutagenesis and In Vivo Assembly

2018 ◽  
Vol 19 (10) ◽  
pp. 2989 ◽  
Author(s):  
Ji Zhang ◽  
Fuying Ma ◽  
Xiaoyu Zhang ◽  
Anli Geng
Keyword(s):  
Directed Evolution ◽  
Laccase Activity ◽  
Catalytic Properties ◽  
Random Mutagenesis ◽  
Catalytic Performance ◽  
Industrial Applications ◽  
Subunit Interaction ◽  
Cerrena Unicolor ◽  
Protein Model

Laccases have great potential for industrial applications due to their green catalytic properties and broad substrate specificities, and various studies have attempted to improve the catalytic performance of these enzymes. Here, to the best of our knowledge, we firstly report the directed evolution of a homodimeric laccase from Cerrena unicolor BBP6 fused with α-factor prepro-leader that was engineered through random mutagenesis followed by in vivo assembly in Saccharomyces cerevisiae. Three evolved fusion variants selected from ~3500 clones presented 31- to 37-fold increases in total laccase activity, with better thermostability and broader pH profiles. The evolved α-factor prepro-leader enhanced laccase expression levels by up to 2.4-fold. Protein model analysis of these variants reveals that the beneficial mutations have influences on protein pKa shift, subunit interaction, substrate entrance, and C-terminal function.

scholarly journals Creating Hybrid Genes by Homologous Recombination

2000 ◽  
Vol 16 (1-2) ◽  
pp. 3-13 ◽  
Author(s):  
Peter L. Wang
Keyword(s):  
Directed Evolution ◽  
High Efficiency ◽  
Genomic Sequence ◽  
Sequence Data ◽  
Strand Breaks ◽  
E Coli ◽  
Hybrid Genes ◽  
Distinct Features

Recombination of homologous genes is a powerful mechanism for generating sequence diversity, and can be applied to protein analysis and directed evolution.In vitrorecombination methods such as DNA shuffling are very flexible and can give hybrid genes with multiple crossovers; they have been used extensively to evolve proteins with improved and novel properties.In vivorecombination in bothE. coliand yeast is greatly enhanced by double-strand breaks; forE. coli, mutant strains are often necessary to obtain high efficiency. Intra- and inter-molecular recombinationIn vivohave distinct features; both give hybrids with one or two crossovers, and have been used to study structure-function relationships of many proteins. Recentlyin vivorecombination has been used to generate diversity for directed evolution, creating a large phage display antibody library. Recombination methods will become increasingly useful in light of the explosion in genomic sequence data and potential for engineered proteins.

Nucleotide Exchange and Excision Technology DNA Shuffling and Directed Evolution

2010 ◽  
pp. 333-344 ◽  
Author(s):  
Janina Speck ◽  
Sabine C. Stebel ◽  
Katja M. Arndt ◽  
Kristian M. Müller
Keyword(s):  
Directed Evolution ◽  
Dna Shuffling ◽  
Nucleotide Exchange

scholarly journals Shuffling the Neutral Drift of Unspecific Peroxygenase inSaccharomyces cerevisiae

2018 ◽  
Vol 84 (15) ◽  
Author(s):  
Javier Martin-Diaz ◽  
Carmen Paret ◽  
Eva García-Ruiz ◽  
Patricia Molina-Espeja ◽  
Miguel Alcalde
Keyword(s):  
Genetic Drift ◽  
Dna Recombination ◽  
Dna Shuffling ◽  
Content Type ◽  
Neutral Drift ◽  
Oxygenase Activity ◽  
Improved Stability ◽  
Neutral Mutations ◽  
Neutral Genetic Drift

ABSTRACTUnspecific peroxygenase (UPO) is a highly promiscuous biocatalyst, and its selective mono(per)oxygenase activity makes it useful for many synthetic chemistry applications. Among the broad repertory of library creation methods for directed enzyme evolution, genetic drift allows neutral mutations to be accumulated gradually within a polymorphic network of variants. In this study, we conducted a campaign of genetic drift with UPO inSaccharomyces cerevisiae, so that neutral mutations were simply added and recombinedin vivo. With low mutational loading and an activity threshold of 45% of the parent's native function, mutant libraries enriched in folded active UPO variants were generated. After only eight rounds of genetic drift and DNA shuffling, we identified an ensemble of 25 neutrally evolved variants with changes in peroxidative and peroxygenative activities, kinetic thermostability, and enhanced tolerance to organic solvents. With an average of 4.6 substitutions introduced per clone, neutral mutations covered approximately 10% of the protein sequence. Accordingly, this study opens new avenues for UPO design by bringing together neutral genetic drift and DNA recombinationin vivo.IMPORTANCEFungal peroxygenases resemble the peroxide shunt pathway of cytochrome P450 monoxygenases, performing selective oxyfunctionalizations of unactivated C-H bonds in a broad range of organic compounds. In this study, we combined neutral genetic drift andin vivoDNA shuffling to generate highly functional peroxygenase mutant libraries. The panel of neutrally evolved peroxygenases showed different activity profiles for peroxygenative substrates and improved stability with respect to temperature and the presence of organic cosolvents, making the enzymes valuable blueprints for emerging evolution campaigns. This association of DNA recombination and neutral drift is paving the way for future work in peroxygenase engineering and, from a more general perspective, to any other enzyme system heterologously expressed inS. cerevisiae.

A semi-rational design strategy of directed evolution combined with chemical synthesis of DNA sequences

2007 ◽  
Vol 388 (12) ◽  
pp. 1291-1300 ◽  
Author(s):  
Ai-Sheng Xiong ◽  
Ri-He Peng ◽  
Jing Zhuang ◽  
Jin-Ge Liu ◽  
Feng Gao ◽  
...  
Keyword(s):  
Directed Evolution ◽  
Dna Sequences ◽  
Active Sites ◽  
Rational Design ◽  
Specific Activity ◽  
Dna Shuffling ◽  
Gene Encoding ◽  
Library Construction ◽  
Key Sites

Abstract Directed evolution in vitro is a powerful molecular tool for the creation of new biological phenotypes. It is unclear whether it is more efficient to mutate an enzyme randomly or to mutate just the active sites or key sites. In this study, the strategy of a semi-rational design of directed evolution combined with whole sequence and sites was developed. The 1553 bp gene encoding the thermostable β-galactosidase of Pyrococcus woesei was chemically synthesized and optimized for G+C content and mRNA secondary structures. The synthesized gene product was used as a template or as a wild-type control. On the basis of the first round of DNA shuffling, library construction and screening, one mutant of YH6754 was isolated with higher activity. Eight potential key sites were deduced from the sequence of the shuffled gene, and 16 degenerate oligonucleotides were designed according to those eight amino acids. Two variants of YG6765 and YG8252 were screened in the second part of DNA shuffling, library construction and screening. For comparison, one mutant of YH8757 was screened through the same routine rounds of directed evolution with YH6754 as template. The purified β-galactosidase from YH8757 exhibited a lower specific activity at 25°C than those purified from mutated YG6755 and YG8252.

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