Open AccessExpression of the collagen adhesin ace by E nterococcus faecalis strain OG 1 RF is not repressed by E rs but requires the E rs box
Author(s) -
Cohen Ana Luisa V.,
Roh Jung Hyeob,
Nallapareddy Sreedhar R.,
Höök Magnus,
Murray Barbara E.
Publication year - 2013
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12146
Subject(s) - enterococcus faecalis , repressor , strain (injury) , bacterial adhesin , biology , microbiology and biotechnology , chemistry , virulence , gene expression , biochemistry , gene , escherichia coli , anatomy
Expression of adhesin to collagen of E nterococcus faecalis ( ace ), a known virulence factor, is increased by environmental signals such as the presence of serum, high temperature, and bile salts. Currently, the enterococcal regulator of survival ( E rs) of E . faecalis strain JH 2‐2 is the only reported repressor of ace . Here, we show that for strain OG 1 RF , E rs is not involved in the regulation of ace . Our data showed similar levels of ace expression by OG 1 RF and its Δers derivative in the presence of bile salts, serum, and high temperature. Using ace promoter‐ lacZ fusions and site‐directed mutagenesis, we confirmed these results and further showed that, while the previously designated E rs box is important for increased expression from the ace promoter of OG 1 RF , the region responsible for the increase is bigger than the E rs box. In summary, these results indicate that, in strain OG 1 RF , E rs is not a repressor of ace expression. Although JH 2‐2 and OG 1 RF differ by six nucleotides in the region upstream of ace as well as in production of F sr and gelatinase, the reason(s) for the difference in ace expression between JH 2‐2 and OG 1 RF and for increased ace expression in bile, serum and at 46 °C remain(s) to be determined.