Regulation of the promoter for capsular polysaccharide synthesis in <i>Neisseria meningitidis</i> serogroup B by HTH_XRE family transcription factor

Pathogenic <i>Neisseria meningitidis</i>, a causal agent of bacterial meningitis, secretes capsular polysaccharides of different compositions that differentiate individual serogroups. Since the capsule is an important virulence factor that determines adhesion to epithelia and ability to invade tissues, there is a need to understand the underlying mechanisms for capsule expression. Furthermore, bacterial polysaccharides are potential sources of novel biomaterials. The expression of the capsule production genes is regulated, and this study reveals a mechanism involving a transcription factor, HTH_XRE, whose function in <i>N. meningitidis</i> is not known. It extends the understanding of capsular expression regulation by identifying other control elements in the intergenic region. The results will have applications in optimizing bacterial biomaterials production or in developing therapeutic interventions.