Open AccessA phosphotransferase system permease is a novel component of C ad C signaling in S almonella enterica
Author(s) -
Lee Yong Heon,
Kim Sinyeon,
Kim Ji Hye,
Bang Iel Soo,
Lee In Soo,
Bang Seong Ho,
Park Yong Keun
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 - 10.1111/1574-6968.12025
Subject(s) - permease , operon , pep group translocation , salmonella enterica , biology , biochemistry , transposon mutagenesis , lysine , signal peptidase , chemistry , gene , transposable element , mutant , signal peptide , escherichia coli , peptide sequence , amino acid
In S almonella enterica serovar T yphimurium, proteolytic cleavage of the membrane‐bound transcriptional regulator C ad C acts as a switch to activate genes of the lysine decarboxylase system in response to low p H and lysine signals. To identify the genetic factors required for the proteolytic activation of C ad C , we performed genome‐wide random mutagenesis. We show that a phosphotransferase system ( PTS ) permease STM 4538 acts as a positive modulator of C ad C function. The transposon insertion in STM4538 reduces the expression of the C ad C target operon cadBA under permissive conditions. In addition, deletional inactivation of STM4538 in the wild‐type background leads to the impaired proteolytic cleavage of C ad C . We also show that only the low p H signal is involved in the proteolytic processing of C ad C , but the lysine signal plays a role in the repression of the lysP gene encoding a lysine‐specific permease, which negatively controls expression of the cadBA operon. Our data suggest that the PTS permease STM 4538 affects proteolytic processing, which is a necessary but not sufficient step for C ad C activation, rendering C ad C able to activate target genes.