XXII. BIOCHEMICKÝ ZJAZD - Jesseniova lekárska fakulta

Posters
44.
CharaCTErIZaTION of SarP rEGULaTOry GENE INvOLvED IN
POSITIve rEGULaTION of an aNGUCYCLINE-LIKE POLYKETIDE
aNTIBIOTICS aurICIN GENE CLUSTEr IN StrePTomyces aureofaCIens
CCM 3239
Alena Reháková, Renáta Nováková , Ľubomíra Fecková,
Peter Kutaš and Ján Kormanec
Institute of Molecular Biology, Slovak Academy of Sciences, Dubravska cesta 21,
845 51 Bratislava, Slovakia
Streptomyces aureofaciens CCM 3239 is gram-positive soil bacterium undergoing a complex
developmental life cycle. During aerial mycelium growth S. aureofaciens CCM 3239
produces their secondary metabolites including antibiotic auricin. The auricin gene cluster
was named aur1. Synthesis of auricin is strictly regulated due to toxicity of auricin and
its regulation is under the complex control of several regulatory genes. The product
of one of these regulatory genes (sa9) belongs to the family of Streptomyces antibiotic
regulatory proteins (SARPs). We characterized this gene and its impact on auricin
production. By using the S1-nuclease mapping we identified a single promoter, sa9p,
which expressed in a narrow stage during growth in rich liquid Bennet medium. The sa9
gene was disrupted by a homologous recombination in S. aureofaciens CCM3239. The
resulting mutant strain had dramatically decreased auricin production. In addition we
confirmed a direct effect of the aur1P regulatory gene upon sa9 expression. The auricin
pathway-specific activator Aur1P directly interacted with the sa9p promoter, indicating
a cascade regulation of auricin production.
Acknowledgement: This work was supported by the Slovak Research and Development
Agency under the contract No. APVV-0017-07.
162 XXII. Biochemistry Congress, Martin