Table I.

Effect of substrates and Glc analogs on the activity of the Fuc transporter of G. sulphuraria

SubstrateFuc Uptake
RepressionNo repression
% %
Hexoses l-Sorbose0Tagatose100
Gal1
Glc3
Man7
Fru28
Deoxysugars l-Rha100
Quinovose95
Pentoses l-Ara100
Xylose70
DisaccharidesTrehalose0
PolyolsSorbitol13 l-Ara124
Mannitol27Xylitol70
Dulcitol70
C3 compoundsGlycerol2Pyruvate86
Methylated sugarsMethyl-Glc8MOG80
Methyl-Man25

Cells were grown on Glc (exponential phase) and transferred to a different substrate. After 3 d, uptake of [14C]Fuc was tested. Uptake of cells transferred to autotrophic medium was taken as 100%. Results are given for one representative set of data. Experiments were repeated at least twice.