Xylose uptake rates of S. cerevisiae strains expressing the Gxf1, Sut1 and At5g59250 transporters determined using D-[U14C] labeled sugar. Cells were grown on 20 g/L glucose. Lines represent the calculated fit according to Michaelis-Menten kinetics. Gxf1, square; Sut1, upwards pointing triangle; At5g59250, diamond; control, downwards pointing triangle. Biological replicates are designated by empty and filled version of the same symbol.