Accelerating pathway evolution by increasing the gene dosage of chromosomal segments
| Autor: | Sarah A. Lee, Jeffrey G. Linger, Melissa P Tumen-Velasquez, Ellen L. Neidle, Mark A. Eiteman, Gregg T. Beckham, Payal Khanna, Emily M. Fulk, Christopher W. Johnson, Ahmed Alaa Ashraf Mahmoud, Graham Dominick, Alicia L. Schmidt |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Experimental evolution Multidisciplinary 030106 microbiology Gene Dosage Computational biology Biological Sciences Chromosomes Bacterial Biology Gene dosage Evolution Molecular Metabolic engineering 03 medical and health sciences chemistry.chemical_compound Synthetic biology 030104 developmental biology Bacterial Proteins chemistry Genes Bacterial Gram-Negative Bacteria Gene duplication Genetic redundancy Guaiacol Gene |
| Zdroj: | Proceedings of the National Academy of Sciences. 115:7105-7110 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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