Sequence determinants spanning -35 motif and AT-rich spacer region impacting Ehrlichia chaffeensis Sigma 70-dependent promoter activity of two differentially expressed p28 outer membrane protein genes.

ABSTRACT: Ehrlichia chaffeensis is an obligate intracellular tick-borne bacterium which causes the disease, human monocytic ehrlichiosis. Ehrlichia chaffeensis contains only two sigma factors, σ32 and σ70. It is difficult to study E. chaffeensis gene regulation due to lack of a transformation system. We developed an Escherichia coli-based transcription system to study E. chaffeensis transcriptional regulation. An E. coli strain with its σ70 repressed with trp promoter is used to express E. chaffeensis σ70. The E. coli system and our previously established in vitro transcription system were used to map transcriptional differences of two Ehrlichia genes encoding p28-outer membrane proteins 14 and 19. We mapped the -10 and -35 motifs and the AT rich spacers located between the two motifs by performing

SUBMITTER: Liu H 

PROVIDER: S-EPMC5066175 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature