An A-Factor-Dependent Extracytoplasmic Function Sigma Factor (ς ^AdsA ) That Is Essential for Morphological Development in Streptomyces griseus

Abstract

AdsA. Transcription of adsA depended on A-factor and AdpA, since adsA was transcribed at a very low and constant level in an A-factor-deficient mutant strain or in an adpA-disrupted strain. Consistent with this, transcription of adsA was greatly enhanced at or near the timing of aerial hyphae formation, as determined by low-resolution S1 nuclease mapping. High-resolution S1 mapping determined the transcriptional start point 82 nucleotides upstream of the translational start codon. DNase I footprinting showed that AdpA bound both strands symmetrically between the transcriptional start point and the translational start codon; AdpA protected the antisense strand from positions ؉7 to ؉41 with respect to the transcriptional start point and the sense strand from positions ؉12 to ؉46. A weak palindrome was found in the AdpA-binding site. The unusual position bound by AdpA as a transcriptional activator, in relation to the promoter, suggested the presence of a mechanism by which AdpA activates transcription of adsA in some unknown way. Disruption of the chromosomal adsA gene resulted in loss of aerial hyphae formation but not streptomycin or yellow pigment production, indicating that AdsA is involved only in morphological development and not in secondary metabolic function. The presence of a single copy in each of the Streptomyces species examined by Southern hybridization suggests a common role in morphogenesis in this genus.

Hormonal control by A-factor of morphological development and secondary metabolism in Streptomyces

“…(i) Genes for morphological differentiation: adsA encoding an ECF factor ( AdsA ), 47) amfR encoding a transcriptional activator for the amf operon, 49),50) ssgA encoding a small acidic protein essential for spore septum formation, 51) genes encoding extracellular proteases including a metalloendopeptidase, 52) two trypsin-type proteases, 53) and three chymotrypsin-type proteases, 54) and a gene for Streptomyces subtilisin inhibitor (SSI).…”

γ-Butyrolactone autoregulator-receptor system involved in lankacidin and lankamycin production and morphological differentiation in Streptomyces rochei

“…The derepressed and produced AdpA protein, a global transcriptional activator, in turn binds to the promoter of strR, a positive regulator gene for streptomycin biosynthesis. Search for additional AdpAbinding DNA sequences identified an ECF sigma factor gene (Yamazaki et al, 2000), a metalloendopeptidase gene (Kato et al, 2002) and many additional genes, which make an AdpA regulon functioning for secondary metabolism and morphological development (Ohnishi et al, 2005). Following the afsA-arpA system, similar c-butyrolactone receptor systems have been found in streptomycetes, for example, the barX-barA system in Streptomyces virginiae (Kawachi et al, 2000), farX-farA in Streptomyces lavendulae (Kitani et al, 2001) and scbA-scbR in S. coelicolor A3(2) (Takano et al, 2001).…”

Conditionally positive effect of the TetR-family transcriptional regulator AtrA on streptomycin production by Streptomyces griseus

“…Bennett agar without glucose [yeast extract, 0.1 %; meat extract (Kyokuto), 0.1 %; NZ amine, 0.2 %; agar, 2 %; pH 7.2] and SMM agar [glucose, 0.9 %; L-asparagine, 0.9 %; (NH 4 ) 2 SO 4 , 0.2 %; Trizma base, 0.24 %; NaCl, 0.1 %; K 2 SO 4 , 0.05 %; MgSO 4 .7H 2 O, 0.02 %; CaCl 2 , 0.01 %; trace element solution (Hopwood et al, 1985), 1 %; agar, 2 %; pH 7.2] containing 2.5 mM KH 2 PO 4 were used for streptomycin assay. The strategies used for gene disruption, alteration of the AtrA-g-binding site by PCR, gel mobility shift assay, DNase I footprinting and S1 nuclease mapping were also described previously (Yamazaki et al, 2000;Hirano et al, 2006). S1 nuclease mapping.…”