007, Fig. 5). The loss of CinA, therefore, enhances the mutant’s sensitivity to killing by MMS, which is likely caused by diminished expression of recA in our SmuCinA mutant or due to a possible interaction with RecA at the DNA replication fork. However, our ability to partially restore viable CFUs by using the CinA complemented strain clearly suggests an important role for CinA in contending with MMS-induced stress in S. mutans. Here we have demonstrated that cinA is transcriptionally regulated by ComX, which in Obeticholic Acid price turn,

modulates genetic competence and cell death in S. mutans. Although, we only investigated CSP’s effects on cinA upregulation, it is likely that cinA also transcriptionally responds to XIP, which was shown to activate ComX (Mashburn-Warren et al., 2010; Lemme et al., 2011). In addition to ComDE, we know that other signaling systems also modulate ComX activity (e.g. ComRS, LiaRS, signaling pathway VicRK) (Mashburn-Warren

et al., 2010; unpublished data). Hence, it stands to reason that ComX-dependent transcription of cinA relies on multiple signaling inputs for optimal activity. Further, our results support the findings of Lemme et al., who showed that ComX can modulate cell death vs. competence depending on its activity (Mashburn-Warren et al., 2010; Lemme et al., 2011). Here, we have further shown that these ComX-regulated phenotypes are, at least in part, regulated via CinA. In this report, we also showed that S. mutans’ ability to withstand DNA damage induced by MMS was also dependent

on CinA. Taken together, we have demonstrated novel roles for the CinA in S. mutans in modulating genetic transformation, cell viability and tolerance to MMS. We would like to thank Martha Cordova for assistance with Northern blots. D.G.C. is a recipient of NIH grant R01DE013230-03 and CIHR-MT15431. “
“The atuR-atuABCDEFGH gene cluster is essential for acyclic terpene utilization (Atu) Dipeptidyl peptidase in Pseudomonas aeruginosa and Pseudomonas citronellolis. The cluster encodes most proteins of the Atu pathway including the key enzyme, geranyl-CoA carboxylase. AtuR was identified as a repressor of the atu gene cluster expression by (1) amino acid similarity to TetR repressor family members, (2) constitutive expression of Atu proteins in the atuR insertion mutant and (3) specific binding of purified AtuR homodimers to the atuR-atuA intergenic region in electrophoretic mobility shift assay (EMSA). Two 13 bp inverted repeat sequences separated by 40 bp in the atuA operator/promoter region were identified to represent two sites of AtuR binding by EMSA. Changing of two or more bases within the inverted repeat sequences abolished the ability of AtuR to bind to its target. All EMSA experiments were sufficiently sensitive with ethidium bromide-stained DNA fragments after polyacrylamide gel electrophoresis.