Sulfate transport in Penicillium chrysogenum: Cloning and characterizationof the sutA and sutB genes

In industrial fermentations, Penicillium chrysogenum uses sulfate as the so urce of sulfur for the biosynthesis of penicillin. By a PCR-based approach, two genes, sutA and sutB, whose encoded products belong to the SulP superf amily of sulfate permeases were isolated. Transformation of a sulfate uptak e-negative sB3 mutant of Aspergillus nidulans with the sutB gene completely restored sulfate uptake activity. The sutA gene did not complement the A. nidulans sB3 mutation, even when expressed under control of the sutB promot er. Expression of both sutA and sutB in P. chrysogenum is induced by growth under sulfur starvation conditions. However, sutA is expressed to a much l ower level than is sutB. Disruption of sutB resulted in a loss of sulfate u ptake ability. Overall, the results show that SutB is the major sulfate per mease involved in sulfate uptake by P. chrysogenum.