Curation Information

Publication

LacR mutations are frequently observed in Streptococcus intermedius and are responsible for increased intermedilysin production and virulence.;Tomoyasu T, Imaki H, Masuda S, Okamoto A, Kim H, Waite RD, Whiley RA, Kikuchi K, Hiramatsu K, Tabata A, Nagamune H;Infection and immunity 2013 Sep; 81(9):3276-86 [23798532]

TF

LacR [T1ZD52, view regulon]

Reported TF sp.

Streptococcus intermedius PC574

Reported site sp.

Streptococcus intermedius PC574

Created by

Dinara Sagitova

Curation notes

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Experimental Process

By measuring the hemolytic activities of the lacR mutant and wild-type cells, the authors identified that lacR mutant cells secreted higher levels of ILY than the wild-type cells. This result was further confirmed by immunoblotting using anti-ILY antibody. qRT-PCR showed that ily expression in lacR mutant cells was 80.7-fold higher than in the wild-type cells. Complementation with lacR restored the expression level to that in the wild type. Biotinylated pulldown assays using whole-cell extracts from S. intermedius PC574 showed that LacR from the whole-cell extracts coprecipitated with PlacD, PlacA, and Pily but did not coprecipitate with the nonspecific DNA probe. The authors report that lacA and lacD promoters contain sequences very similar to the LacR consensus, TGTTTNWTTT(where N is any base and W is A or T), whereas the ily promoter does not have any homology to the LacR recognition element.

Transcription Factor Binding Sites

• Sites reported in the paper
• Sites matched in the genome

Gene Regulation

Regulated genes for each binding site are displayed below. Gene regulation diagrams show binding sites, positively-regulated genes, negatively-regulated genes, both positively and negatively regulated genes, genes with unspecified type of regulation. For each indvidual site, experimental techniques used to determine the site are also given.