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ZrFsy1, a high-affinity fructose/H+ symporter from fructophilic Zygosaccharomyces rouxii
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Orientador(es)
Resumo(s)
Zygosaccharomyces rouxii is a fructophilic yeast than can grow at very high sugar concentrations. We have identified an ORF
encoding a putative fructose/H+ symporter in the Z. rouxii CBS 732 genome database. Heterologous expression of this ORF
in a S. cerevisiae strain lacking its own hexose transporters (hxt-null) and subsequent kinetic characterization of its sugar
transport activity showed it is a high-affinity low-capacity fructose/H+ symporter, with Km 0.4560.07 mM and Vmax
0.5760.02 mmol h21 (gdw) 21. We named it ZrFsy1. This protein also weakly transports xylitol and sorbose, but not glucose
or other hexoses. The expression of ZrFSY1 in Z. rouxii is higher when the cells are cultivated at extremely low fructose
concentrations (,0.2%) and on non-fermentable carbon sources such as mannitol and xylitol, where the cells have a
prolonged lag phase, longer duplication times and change their microscopic morphology. A clear phenotype was
determined for the first time for the deletion of a fructose/H+ symporter in the genome where it occurs naturally. The effect
of the deletion of ZrFSY1 in Z. rouxii cells is only evident when the cells are cultivated at very low fructose concentrations,
when the ZrFsy1 fructose symporter is the main active fructose transporter system
Descrição
Palavras-chave
Zygosaccharomyces rouxii fructose
Contexto Educativo
Citação
Leandro MJ, Sychrova´ H, Prista C, Loureiro-Dias MC (2013) ZrFsy1, a High-Affinity Fructose/H+ Symporter from Fructophilic Yeast Zygosaccharomyces rouxii. PLoS ONE 8(7): e68165
Editora
PlosOne