Evolution of a novel chimeric maltotriose transporter in Saccharomyces eubayanus from parent proteins unable to perform this function
| Autor: | Jack T. Pronk, Susan M Weening, Tom D. Elink Schuurman, Arthur R. Gorter de Vries, Marcel van den Broek, Niels G. A. Kuijpers, Nick Brouwers, Jean-Marc Daran |
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| Rok vydání: | 2019 |
| Předmět: |
Evolutionary Genetics
Models Molecular Cancer Research Mutant Yeast and Fungal Models QH426-470 Saccharomyces Database and Informatics Methods chemistry.chemical_compound 0302 clinical medicine Fungal Evolution Evolutionary Emergence Genetics (clinical) Liquid Chromatography Recombination Genetic 0303 health sciences biology Organic Compounds Monosaccharides Chromatographic Techniques Saccharomyces eubayanus Eukaryota Beer Chemistry Experimental Organism Systems Biochemistry Physical Sciences Saccharomyces Cerevisiae Neofunctionalization Sequence Analysis Research Article Evolutionary Processes Bioinformatics Recombinant Fusion Proteins Genes Fungal Saccharomyces cerevisiae Carbohydrates Mycology Research and Analysis Methods Fungal Proteins 03 medical and health sciences Model Organisms Genetics Maltotriose Gene family Maltose Molecular Biology Gene Ecology Evolution Behavior and Systematics 030304 developmental biology Evolutionary Biology Whole Genome Sequencing Organic Chemistry Organisms Fungi Chemical Compounds Biology and Life Sciences biology.organism_classification Yeast High Performance Liquid Chromatography Protein Structure Tertiary Glucose chemistry Genetic Loci Mutagenesis Fermentation Animal Studies Hybridization Genetic Directed Molecular Evolution Carrier Proteins Sequence Alignment Trisaccharides 030217 neurology & neurosurgery |
| Zdroj: | PLoS Genetics, Vol 15, Iss 4, p e1007853 (2019) PLoS Genetics (Print), 15(4) PLoS Genetics |
| ISSN: | 1553-7404 1553-7390 |
| DOI: | 10.1371/journal.pgen.1007853 |
| Popis: | Saccharomyces eubayanus is the non-S. cerevisiae parent of the lager-brewing hybrid S. pastorianus. In contrast to most S. cerevisiae and Frohberg-type S. pastorianus strains, S. eubayanus cannot utilize the α-tri-glucoside maltotriose, a major carbohydrate in brewer’s wort. In Saccharomyces yeasts, utilization of maltotriose is encoded by the subtelomeric MAL gene family, and requires transporters for maltotriose uptake. While S. eubayanus strain CBS 12357T harbors four SeMALT genes which enable uptake of the α-di-glucoside maltose, it lacks maltotriose transporter genes. In S. cerevisiae, sequence identity indicates that maltotriose and maltose transporters likely evolved from a shared ancestral gene. To study the evolvability of maltotriose utilization in S. eubayanus CBS 12357T, maltotriose-assimilating mutants obtained after UV mutagenesis were subjected to laboratory evolution in carbon-limited chemostat cultures on maltotriose-enriched wort. An evolved strain showed improved maltose and maltotriose fermentation in 7 L fermenter experiments on industrial wort. Whole-genome sequencing revealed a novel mosaic SeMALT413 gene, resulting from repeated gene introgressions by non-reciprocal translocation of at least three SeMALT genes. The predicted tertiary structure of SeMalT413 was comparable to the original SeMalT transporters, but overexpression of SeMALT413 sufficed to enable growth on maltotriose, indicating gene neofunctionalization had occurred. The mosaic structure of SeMALT413 resembles the structure of S. pastorianus maltotriose-transporter gene SpMTY1, which has high sequences identity to alternatingly S. cerevisiae MALx1, S. paradoxus MALx1 and S. eubayanus SeMALT3. Evolution of the maltotriose transporter landscape in hybrid S. pastorianus lager-brewing strains is therefore likely to have involved mechanisms similar to those observed in the present study. Author summary Fermentation of the wort sugar maltotriose is critical for the flavor profile obtained during beer brewing. The recently discovered yeast Saccharomyces eubayanus is gaining popularity as an alternative to S. pastorianus and S. cerevisiae for brewing, however it is unable to utilize maltotriose. Here, a combination of non-GMO mutagenesis and laboratory evolution of the S. eubayanus type strain CBS 12357T was used to enable maltotriose fermentation and improve brewing performance. The improved strain expressed a novel transporter gene, SeMALT413, which was formed by recombination between three different SeMALT maltose-transporter genes. Overexpression of SeMALT413 in CBS 12357T confirmed its neofunctionalization as a maltotriose transporter. As the S. pastorianus maltotriose transporter SpMty1 has a mosaic structure similar to SeMalT413, maltotriose utilization likely involved similar recombination events during the domestication of current lager brewing strains. Based on a posteriori sequence analysis, the emergence of gene functions has been attributed to gene neofunctionalization in a broad range of organisms. The real-time observation of neofunctionalization during laboratory evolution constitutes an important validation of the relevance and importance of this mechanism for Darwinian evolution. |
| Databáze: | OpenAIRE |
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