Research objectives and content
The aim of this study is a better unterstanding of the biosynthesis of polyketides, especially of formation the lacton ring. Therefore we will overproduce several essential polyketide synthase domains, mainly a acetyl transferase, a Beta-ketoacyl synthase, an acyl transferase and an acyl carrier protein, in E. coli and / or Saccharopolyspora erythrea. The recombinant proteins will be purified and examined for their catalytic activities. Therefore we will investigate the modification of ACP with the cofactor 4'-phosphopantetheine. This will allow the development of new enzymatic assays for exploring the catalytic activties of the Beta-ketoacyl synthase domain. Furthermore, this could be a first step towards a complete in vitro biosynthesis of macrolactone rings. Another aspect will be the crystallization of the domains in order to obtain precious insights into the three-dimensional structure. These findings will allow to determine, which aa-residues are important for catalytic activity or interactions with other domains. Subsequently, it would be possible to point out the functions of these aa-residues by mutational analysis.
Training content (objective, benefit and expected impact)
After investigating the non-ribosomal biosynthesis of peptide-antibiotics, it will be very interesting for me to extend this knowledge to a new challenging field of antibiotic-research. Producing polyketide synthase domains domains and investigating the catalytic activities of these recombinant proteins will offer me a good opportunity to gain experience with Actinomycetes such as Streptomyces and Saccharopolyspora and the enzymology of polyketide biosynthesis.
Links with industry / industrial relevance
As far as this study is concerned, there will be no direct collaborations with industry. Because many companies are likewise investigating polyketide biosynthesis in order to obtain new efficient antibiotics or to increase the rate of the in vivo biosynthesis, it can be assumed, that this study will be interesting for the industry.