Dual control by regulators, GntH and GntR, of the Gntll genes for gluconate metabolism in Escherichia coli

作者：Tsunedomi R^*; Izu H; Kawai T; Yamada M

来源：Journal of Molecular Microbiology and Biotechnology, 2003, 6(1): 41-56.

DOI：10.1159/000073407

• gluconate metabolism
• Gntll
• gntR
• gntH
• divergent promoter
• expressional regulation

Escherichia coli possesses two systems, Gntl and Gntll, for gluconate uptake and catabolism, whose genes are regulated by GntR as a repressor and GntH as an activator, respectively. Additionally, GntH exerts negative control of the Gntl genes via the same binding element as that of GntR. We thus examined whether GntR involves regulation of the Gntll genes or not. This regulation and the control by GntH were examined by using single-copy /ac Zoperon fusions and by RT-PCR, suggesting positive and negative regulation by GntR and positive regulation by GntH. Moreover, the introduction of mutations into possible GntR-binding elements revealed that both regulators share at least one of the elements. The results presented allow us to speculate that GntR initiates expression of the Gntll genes, followed by their large induction by GntH when cells were grown in gluconate minimum medium. As in the case of the Gntl genes, such a cross-regulation between the Gntl and Gntll via the two regulators may be important for cells to grow with gluconate.

• 出版日期2003