Characterization of a Novel Fucose-Regulated Promoter (P fcsK ) Suitable for Gene Essentiality and Antibacterial Mode-of-Action Studies in Streptococcus pneumoniae

Abstract

ABSTRACT The promoter of the Streptococcus pneumoniae putative fuculose kinase gene ( fcsK ), the first gene of a novel fucose utilization operon, is induced by fucose and repressed by glucose or sucrose. When the streptococcal polypeptide deformylase (PDF) gene ( def1 , encoding PDF) was placed under the control of P fcsK , fucose-dependent growth of the S. pneumoniae (P fcsK :: def1 ) strain was observed, confirming the essential nature of PDF in this organism. The mode of antibacterial action of actinonin, a known PDF inhibitor, was also confirmed with this strain. The endogenous fuculose kinase promoter is a tightly regulated, titratable promoter which will be useful for target validation and for confirmation of the mode of action of novel antibacterial drugs in S. pneumoniae .