The transport of glucose and maltose in Saccharomyces cerevisiae was observed to occur by both high and low affinity transport systems. A spontaneously isolated 2-deoxy-D-glucose resistant mutant was observed to transport glucose and maltose only by the high affinity transport systems. Associated with this was an increase in the V max values, indicating derepression of the high affinity transport systems. The low affinity transport systems could not be detected. This mutant will be important in examining the repression regulatory and sugar transport mechanisms in yeast.
