XXII. BIOCHEMICKÝ ZJAZD - Jesseniova lekárska fakulta

Posters
37.
StrICT CONTrOL of aurICIN prODUCTION IN StrePTomyces
aureofaCIens CCM 3239 INvOLvES a fEEDBaCK MECHaNISM
Peter Kutaš, Ľubomíra Fecková, Alena Reháková,
Renáta Nováková and Ján Kormanec
Institute of Molecular Biology, Slovak Academy of Sciences, Dubravska cesta 21,
845 51 Bratislava, Slovakia
In Streptomyces aureofaciens CCM 3239, we have previously identified a type II polyketide
synthase gene cluster, aur1, responsible for production of the angucycline-like antibiotic
auricin. We found out, that auricin was produced at very specific stage and afterwards
it was degraded to a non-active metabolite(s). Two regulatory genes, aur1P and aur1R,
whose deduced products share significant similarity with two different types of bacterial
regulatory proteins, were investigated in order to reveal tight regulation in S. aureofaciens
CCM 3239. Expression of the auricin biosynthetic genes is under control of the
pathway-specific positive regulator Aur1P that belongs to the family of response regulators
of bacterial two-component signal transduction systems. Transcriptional analysis
revealed that the activity of the identified aur1Ap promoter is dramatically decreased
in later stages of stationary phase and the promoter is directly activated by the auricin
pathway specific activator Aur1P at the entry to stationary phase. Aur1P was shown to
bind specifically the aur1Ap promoter and this binding was abolished by the presence
of auricin and/or its intermediates. In addition, the aur1Pp promoter was negatively
regulated by the TetR family Aur1R repressor, and its binding to the promoter was also
obolished by the presence of an auricin intermediate(s). The results indicate specific
feed-back mechanism of auricin production in S. aureofaciens CCM 3239.
Acknowledgements: This work was supported by the Slovak Research and Development
Agency under the contract No. APVV-0017-07.
XXII. Biochemistry Congress, Martin
155