Transcriptome analysis of streptococus mutans UA159 and SMU_1995c knock out strain

Zinc is an essential divalent trace metal for living cells. Intracellular zinc homeostasis is critical to the pathogenicity and virulence of bacteria, however the strategies of zinc homeostasis maintain in Streptococcus mutans, an important causative pathogen of dental caries, is unknown. In this study, we examined the function of an ABC transporter AdcCBA and its transcription factor AdcR in S. mutans. Using RNA-Seq analysis, LacZ-reporter studies and gel mobility shift assay, we showed that a MarR family transcription factor AdcR directly regulates the activity of promoters of adcRCB and adcA in response to the concentration of zinc in their environmental niches. Deletion of adcR increases the sensitivity of S. mutans to excessive zinc supply. Taken together, our finding suggests that Adc regulon, consists of a zinc uptake transporter AdcCBA and a zinc-responsive repressor AdcR, plays a prominent role in the maintenance of intracellular zinc homeostasis of S. mutans. mRNA profiles of wild type UA159 and its SMU_1995c deletion mutant