Studies of the two-component signal transduction system RR/HK06 in Streptococcus pneumoniae.

Abstract

Streptococcus pneumoniae (the pneumococcus) is a major human pathogen responsible for significant morbidity and mortality worldwide. Pneumococcal disease, which can include both invasive conditions such as pneumonia, bacteremia and meningitis, as well as less severe conditions such as otitis media, is almost invariably preceded by asymptomatic colonisation of the nasopharynx. To successfully adapt to the different ecological niches it encounters, the pneumococcus is likely to rely on the co-ordinated regulation of key virulence factors. As is the case for many other prokaryotes, this is likely to occur through two-component signal transduction systems (TCSTSs). TCSTSs comprise a histidine kinase (HK) and response regulator (RR). They respond to environmental stimuli, and regulate gene expression by interacting with the transcription machinery. Thirteen complete TCSTSs have been identified in S. pneumoniae, along with a lone RR. This study focused on one of these systems, designated RR/HK06.