An adpA homologue in Streptomyces avermitilis is involved in regulation of morphogenesis and melanogenesis

Abstract

In Streptomyces griseus, AdpA, the key transcriptional activator in the A-factor regulatory cascade, switches on the transcription of multiple genes required for secondary metabolism and morphological differentiation. Streptomyces avermitilis also contains an ortholog of adpA, which is named adpA-a. To clarify the in vivo function of adpA-a, an adpA-a-disrupted strain was constructed by double crossover recombination. No difference in avermectin production was found between the adpA-a-disruptant and the wild-type strain. However, this disruptant neither formed spores nor produced melanin and its phenotype was restored to the original wild-type by a single copy of the adpA-a gene integrated into the chromosome. This report shows that adpA-a is involved in regulation of morphological differentiation and melanin production in S. avermitilis.