Figure 5.

Genetic organization and transcriptional profile of the TDC cluster in E. durans IPLA655. Promoters (P) and termination regions are indicated. The different mRNA are represented by wavy lines. Numbers indicate the size of the corresponding gene in base pairs (bp). Regulation of the genes by tyrosine and pH is indicated below. Acidic pH is required for optimal expression of the three genes. In addition, tdcA and tyrP are positively regulated by 10 mM tyrosine (+Y), whereas expression of tyrS is negatively affected by tyrosine (+: positively regulated; -: negatively regulated; tyrS: tyrosyl-tRNA synthetase; tdcA: tyrosine decarboxylase; tyrP: tyrosine-tyramine antiporter). Structures upstream tyrS represent the stems I, II, III and terminator of the leader region. The terminator/antiterminator mechanism that regulates the tyrS gene is also indicated: readthrough of the leader region is induced by limitation of tyrosine. Uncharged tyrtRNA stabilize formation of antiterminator structure in the mRNA, which prevents terminator formation (SD: Shine-Dalgarno; ORF: open reading frame of tyrS)

Linares et al. BMC Microbiology 2012 12:23   doi:10.1186/1471-2180-12-23
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