Characterization of an A-factor-responsive repressor for amfR essential for onset of aerial mycelium formation in Streptomyces griseus.

ABSTRACT: A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) is essential for the initiation of aerial mycelium formation in Streptomyces griseus. amfR is one of the genes which, when cloned on a low-copy-number plasmid, suppresses the aerial mycelium-negative phenotype of an A-factor-deficient mutant of S. griseus. Disruption of the chromosomal amfR gene resulted in complete abolition of aerial mycelium formation, indicating that amfR is essential for the onset of morphogenesis. Cloning and nucleotide sequencing of the region upstream of amfR predicted an operon consisting of orf5, orf4, and amfR. Consistent with this idea, Northern blotting and S1 mapping analyses suggested that these three genes were cotranscribed mainly by a promoter (PORF5) in front of orf5. Furthermore, PORF5 was a

SUBMITTER: Ueda K 

PROVIDER: S-EPMC107543 | biostudies-literature | 1998 Oct

REPOSITORIES: biostudies-literature