Striking a Balance Within: Characterizing Putative Efflux Transporters in the Oral Pathogen, Streptococcus mutans, Poster 24

Streptococcus mutans is a commensal member of the oral microbiome and the primary causative agent of dental caries. Research in the Spatafora laboratory has focused on a 25-kDa SloR metalloregulatory protein in S. mutans, and... [ view full abstract ]

Streptococcus mutans is a commensal member of the oral microbiome and the primary causative agent of dental caries. Research in the Spatafora laboratory has focused on a 25-kDa SloR metalloregulatory protein in S. mutans, and its role as a potential target for developing an anti-caries therapeutic. Previous work conducted in our laboratory demonstrated manganese- and SloR-dependent repression of the sloABC metal ion uptake operon in S. mutans. The present work marks the beginning of a new avenue of inquiry in the Spatafora laboratory by investigating the molecular mechanisms of manganese efflux in S. mutans. In this study, we used a combination of bioinformatic and genetic approaches to identify the yeaB and mntE genes that encode putative manganese efflux transporters that we propose facilitate essential metal ion homeostasis in S. mutans. To address this hypothesis, I used a PCR-ligation mutagenesis approach to introduce an insertion-deletion mutation into the coding region of yeaB which I subsequently confirmed in PCR and nucleotide sequencing experiments. Metal ion sensitivity assays are currently ongoing to reveal whether metal ion homeostasis is impacted by the yeaB mutation, and whether YeaB plays a functional role in metal ion efflux. These studies are significant because they can elucidate, for the first time in this important oral pathogen, whether cation efflux is important for maintaining a delicate balance of intracellular metal ions that is essential for S. mutans survival and caries formation.