Fig. 4.
The inducible surP promoter (a) and constitutive ribonuclease HIII promoter (b) were used to express reporter proteins alpha-galactosidase (AgaN) and superfolding green fluorescent protein (sfGFP), respectively. a GsNUB3621 were transformed with the empty E. coli/GsNUB3621 shuttle vector pNW33N (blue) or surT-PsurP-agaN-pNW33N (green). The transformants were propagated overnight in modified LB medium, in the presence (solid lines) or absence (dotted lines) of sucrose. The supernatants were reacted with 4-methylumbelliferyl-alpha-D-galactopyranoside. Aliquots were quenched in sodium hydroxide; the alpha-galactosidase activity (increase in fluorescence over time) was measured in a spectrofluorimeter. b GsNUB3621 was transformed with the empty pNW33N vector (blue) or expression vector PRHIII-sfGFP--pNW33N (green). The transformants were propagated overnight in mLB medium. The cells were harvested by centrifugation, resuspended in buffer, and lysed by lysozyme-catalyzed hydrolysis of their cell walls. The fluorescence spectra were measured; the values were adjusted by subtracting the fluorescence of a blank (fresh mLB)