Conditionally positive effect of the TetR-family transcriptional regulator AtrA on streptomycin production by Streptomyces griseus.
AtrA, a transcriptional activator for actII-ORF4, encoding the pathway-specific transcriptional activator of the actinorhodin biosynthetic gene cluster in Streptomyces coelicolor A3(2), has been shown to bind the region upstream from the promoter of strR, encoding the pathway-specific transcriptional activator of the streptomycin biosynthetic gene cluster in Streptomyces griseus [Uguru et al. (2005) Mol Microbiol 58, 131-150]. The atrA orthologue (atrA-g) in S. griseus was constitutively transcribed throughout growth from a promoter located about 250 nt upstream of the translational start codon, as determined by S1 nuclease mapping. DNase I footprinting showed that histidine-tagged AtrA-g bound an inverted repeat located upstream of strR at positions -117 to -142 relative to the transcriptional start point of strR as +1. This AtrA-g-binding site was between two AdpA-binding sites at approximately nucleotide positions -270 and -50. AdpA is a central transcriptional activator in the A-factor regulatory cascade and essential for the transcription of strR. AtrA-g and AdpA simultaneously bound the respective binding sites. In contrast to AdpA, AtrA-g was non-essential for strR transcription; an atrA-g-disrupted strain produced streptomycin on routine agar media to the same extent as the wild-type strain. However, the atrA-g-disrupted strain tended to produce a smaller amount of streptomycin than the wild-type strain under some conditions, for example, on Bennett agar containing 1 % maltose and on a minimal medium. Therefore, AtrA-g had a conditionally positive effect on streptomycin production, as a tuner, probably by enhancing the AdpA-dependent transcriptional activation of strR in a still unknown manner.
Hirano
Setsu
S
Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
Tanaka
Katsuyuki
K
Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
Ohnishi
Yasuo
Y
Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
Horinouchi
Sueharu
S
Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D018983:DNA Footprinting; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D048372:Streptomyces coelicolor / Q000235:genetics; D013305:Streptomyces griseus / Q000502:physiology*; D013307:Streptomycin / Q000096:biosynthesis*; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D024363:Transcription Initiation Site
C401645:AdpA protein, Streptomyces griseus; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C098255:StrR protein, Streptomyces griseus; D015534:Trans-Activators; D014157:Transcription Factors; D013307:Streptomycin