Engineering of yeast hexose transporters to transport D-xylose without inhibition by D-glucose.

ABSTRACT: All known D-xylose transporters are competitively inhibited by D-glucose, which is one of the major reasons hampering simultaneous fermentation of D-glucose and D-xylose, two primary sugars present in lignocellulosic biomass. We have set up a yeast growth-based screening system for mutant D-xylose transporters that are insensitive to the presence of D-glucose. All of the identified variants had a mutation at either a conserved asparagine residue in transmembrane helix 8 or a threonine residue in transmembrane helix 5. According to a homology model of the yeast hexose transporter Gal2 deduced from the crystal structure of the D-xylose transporter XylE from Escherichia coli, both residues are found in the same region of the protein and are positioned slightly to the extracellular side of the

SUBMITTER: Farwick A 

PROVIDER: S-EPMC3986176 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature