Guanosine tetraphosphate relieves the negative regulation of Salmonella pathogenicity island-2 gene transcription exerted by the AT-rich ssrA discriminator region.

ABSTRACT: The repressive activity of ancestral histone-like proteins helps integrate transcription of foreign genes with discrepant AT content into existing regulatory networks. Our investigations indicate that the AT-rich discriminator region located between the -10 promoter element and the transcription start site of the regulatory gene ssrA plays a distinct role in the balanced expression of the Salmonella pathogenicity island-2 (SPI2) type III secretion system. The RNA polymerase-binding protein DksA activates the ssrAB regulon post-transcriptionally, whereas the alarmone guanosine tetraphosphate (ppGpp) relieves the negative regulation imposed by the AT-rich ssrA discriminator region. An increase in the GC-content of the ssrA discriminator region enhances ssrAB transcription and SsrB translatio

SUBMITTER: Tapscott T 

PROVIDER: S-EPMC6013443 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature