Contribution of σ 70 and σ N Factors to Expression of Class II pilE in Neisseria meningitidis

Abstract

The type four pilus (Tfp) of Neisseria meningitidis contributes to fundamental processes such as adhesion, transformation, and disease pathology. Meningococci express one of two distinct classes of Tfp (class I or class II), which can be distinguished antigenically or by the major subunit ( pilE ) locus and its genetic context. The factors that govern transcription of the class II pilE gene are not known, even though it is present in isolates that cause epidemic disease. Here we show that the transcription of class II pilE is maintained throughout growth and under different stress conditions and is driven by a σ 70 -dependent promoter. This is distinct from Tfp regulation in nonpathogenic Neisseria spp. and may confer an advantage during host-cell interaction and infection.