Accelerating pathway evolution by increasing the gene dosage of chromosomal segments.

Autor:	Tumen-Velasquez M; Department of Microbiology, University of Georgia, Athens, GA 30602., Johnson CW; National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401., Ahmed A; Department of Microbiology, University of Georgia, Athens, GA 30602., Dominick G; National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401., Fulk EM; National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401., Khanna P; National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401., Lee SA; School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602., Schmidt AL; Department of Microbiology, University of Georgia, Athens, GA 30602., Linger JG; National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401., Eiteman MA; Department of Microbiology, University of Georgia, Athens, GA 30602.; School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602., Beckham GT; National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401; gregg.beckham@nrel.gov eneidle@uga.edu., Neidle EL; Department of Microbiology, University of Georgia, Athens, GA 30602; gregg.beckham@nrel.gov eneidle@uga.edu.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2018 Jul 03; Vol. 115 (27), pp. 7105-7110. Date of Electronic Publication: 2018 Jun 18.
DOI:	10.1073/pnas.1803745115
Abstrakt:	Experimental evolution is a critical tool in many disciplines, including metabolic engineering and synthetic biology. However, current methods rely on the chance occurrence of a key step that can dramatically accelerate evolution in natural systems, namely increased gene dosage. Our studies sought to induce the targeted amplification of chromosomal segments to facilitate rapid evolution. Since increased gene dosage confers novel phenotypes and genetic redundancy, we developed a method, Evolution by Amplification and Synthetic Biology (EASy), to create tandem arrays of chromosomal regions. In Acinetobacter baylyi , EASy was demonstrated on an important bioenergy problem, the catabolism of lignin-derived aromatic compounds. The initial focus on guaiacol (2-methoxyphenol), a common lignin degradation product, led to the discovery of Amycolatopsis genes ( gcoAB ) encoding a cytochrome P450 enzyme that converts guaiacol to catechol. However, chromosomal integration of gcoAB in Pseudomonas putida or A. baylyi did not enable guaiacol to be used as the sole carbon source despite catechol being a growth substrate. In ∼1,000 generations, EASy yielded alleles that in single chromosomal copy confer growth on guaiacol. Different variants emerged, including fusions between GcoA and CatA (catechol 1,2-dioxygenase). This study illustrates the power of harnessing chromosomal gene amplification to accelerate the evolution of desirable traits. Competing Interests: The authors declare no conflict of interest.
Databáze:	MEDLINE
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