Open AccessNATURAL MUTATION IN THE GENE OF RESPONSE REGULATOR BgrR RESULTING IN REPRESSION OF Bac PROTEIN SYNTHESIS, A PATHOGENICITY FACTOR OF STREPTOCOCCUS AGALACTIAE
Author(s) -
А. С. Рождественская,
Ilda Santos-Sanches,
А. В. Дмитриев
Publication year - 2014
Publication title -
infekciâ i immunitet
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.137
H-Index - 5
eISSN - 2313-7398
pISSN - 2220-7619
DOI - 10.15789/2220-7619-2013-1-43-48
Subject(s) - streptococcus agalactiae , virulence , biology , gene , virulence factor , microbiology and biotechnology , response regulator , psychological repression , genetics , regulator gene , regulation of gene expression , gene expression , mutant , streptococcus , bacteria
. Streptococcus agalactiae can cause variety of diseases of newborns and adults. For successful colonization of different human tissues and organs as well as for suppression of the host immune system S. agalactiae expresses numerous virulence factors. For coordinated expression of the virulence genes S. agalactiae employs regulatory molecules including regulatory proteins of two-component systems. Results of the present study demonstrated that in S. agalactiae strain A49V the natural mutation in the brgR gene encoding for BgrR regulatory protein, which is component of regulatory system BgrRS, resulted in the repression of Bac protein synthesis, a virulence factor of S. agalactiae. A single nucleotide deletion in the bgrR gene has caused a shift of the reading frame and the changes in the primary, secondary and tertiary structures of the BgrR protein. The loss of functional activity of BgrR protein in A49V strain and repression of Bac protein synthesis have increased virulence of the strain in experimental animal streptococcal infection.