The Functional ccpA Gene Is Required for Carbon Catabolite Repression in Lactobacillus plantarum
AUTOR(ES)
Muscariello, Lidia
FONTE
American Society for Microbiology
RESUMO
We report the characterization of the ccpA gene of Lactobacillus plantarum, coding for catabolite control protein A. The gene is linked to the pepQ gene, encoding a proline peptidase, in the order ccpA-pepQ, with the two genes transcribed in tandem from the same strand as distinct transcriptional units. Two ccpA transcription start sites corresponding to two functional promoters were found, expression from the upstream promoter being autogenously regulated through a catabolite-responsive element (cre) sequence overlapping the upstream +1 site. During growth on ribose, the upstream promoter showed maximal expression, while growth on glucose led to transcription from the downstream promoter. In a ccpA mutant strain, the gene was transcribed mainly from the upstream promoter in both repressing and non repressing conditions. Expression of two enzyme activities, β-glucosidase and β-galactosidase, was relieved from carbon catabolite repression in the ccpA mutant strain. In vivo footprinting analysis of the catabolite-controlled bglH gene regulatory region in the ccpA mutant strain showed loss of protection of the cre under repressing conditions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=92959Documentos Relacionados
- Carbon Catabolite Repression in Lactobacillus pentosus: Analysis of the ccpA Region
- Catabolite repression in Lactobacillus casei ATCC 393 is mediated by CcpA.
- Mutations in Catabolite Control Protein CcpA Separating Growth Effects from Catabolite Repression
- Expression of the bglH Gene of Lactobacillus plantarum Is Controlled by Carbon Catabolite Repression
- Catabolite repression of the Bacillus subtilis gnt operon mediated by the CcpA protein.