Characterization of the sat operon in Streptococcus mutans: evidence for a role of Ffh in acid tolerance.

ABSTRACT: An essential protein translocation pathway in Escherichia coli and Bacillus subtilis involves the signal recognition particle (SRP), of which the 54-kDa homolog (Ffh) is an essential component. In a previous study, we found that a transposon insertion in the ylxM-ffh intergenic region of the designated secretion and acid tolerance (sat) operon of Streptococcus mutans resulted in an acid-sensitive phenotype. In the present study, we further characterized this genomic region in S. mutans after construction of bona fide sat operon mutants and confirmed the role of the SRP pathway in acid resistance. Northern blot and primer extension analyses identified an acid-inducible promoter upstream of ylxM that was responsible for upregulating the coordinate expression of all five genes of the sat oper

SUBMITTER: Kremer BH 

PROVIDER: S-EPMC95171 | biostudies-literature | 2001 Apr

REPOSITORIES: biostudies-literature