Identification of a complex operator for galP1, the glucose-sensitive, galactose-dependent promoter of the Streptomyces galactose operon.

AUTOR(ES)

Mattern, S G

RESUMO

The galP1 promoter is responsible for galactose-dependent, glucose-sensitive transcription of the galactose utilization operon of Streptomyces coelicolor and Streptomyces lividans. We describe the characterization of mutations that were positioned directly upstream of the apparent transcription start site of galP1 and that resulted in deregulated expression. Certain combinations of base changes within a series of hexamers that lie within two pairs of direct repeat sequences resulted in significant expression from galP1 in the absence of inducer. These motifs are further implicated in regulation by the observation that DNA fragments containing the hexamers and direct repeat sequences resulted in increased transcription from the chromosomal copy of galP1 on multicopy plasmids in the absence of galactose. We suggest that these hexamers and direct repeat sequences constitute an operator for the negative regulation of the Streptomyces gal operon.

Documentos Relacionados

• Galactose-dependent reversible interaction of Gal3p with Gal80p in the induction pathway of Gal4p-activated genes of Saccharomyces cerevisiae
• xylE functions as an efficient reporter gene in Streptomyces spp.: use for the study of galP1, a catabolite-controlled promoter.
• 2-deoxygalactose, a specific substrate of the Salmonella typhiimurium galactose permease: its use for the isolation of galP mutants.
• Regulation of galactose operon at the gal operator-promoter region in Escherichia coli K-12.
• Gene organization and structure of the Streptomyces lividans gal operon.