Analysis of Streptomyces ghanaensis ATCC14672 gene SSFG_07725 for putative γ-butyrolactone synthase.

Low molecular weight signaling compounds (LMWC) are important players in regulating various aspects of Streptomyces biology. Their exact roles in certain strain will ultimately depend on overall configuration of regulatory network and thus cannot be predicted on basis of in silico studies. Here, we explored S. ghanaensis gene SSFG_07725 (afsAgh) presumably involved in initial steps of formation of γ-butyrolactone LMWC. Disruption of afsAgh impaired aerial mycelium formation and increased the transcription of pleiotropic regulatory gene adpAgh, whereas level of moenomycin production remained virtually unaffected. We provide evidence that morphogenetic deficiency of afsAgh-minus mutant was caused by inability to produce diffusible LMWC. Possible links between γ-butyrolactone signaling and various aspects of S. ghanaensis biology are discussed.

The adpA-like regulatory gene from Actinoplanes teichomyceticus: in silico analysis and heterologous expression.

Analysis of the draft sequence of the genome of teicoplanin producer Actinoplanes teichomyceticus (NRRL-B16726) led to identification of several genes encoding AraC-family regulators that resemble AdpA, master regulator of transcription in Streptomyces. We elucidated possible regulatory functions of one of the identified genes, adpA19(at), most similar to archetypal adpA from model Streptomyces species, in a series of expression experiments. Introduction of adpA19 at under control of its own promoter on moderate copy number vector pKC1139 into NRRL-B16726 had no influence on antibiotic production and sporulation. Introduction of adpA19 at into Streptomyces coelicolor M145 and several S. ghanaensis strains had major influence on antibiotic production by these bacteria. Finally, adpA19 at expression in a set of soil actinomycete isolates led to induction of synthesis of antibiotic compounds. Our data point to pleiotropic regulatory role of adpA19(at), warranting its use as a tool to manipulate secondary metabolome of actinomycetes.