Non-ribosomal peptide synthesis

• Applicant: Professor Dr. Mohamed A. Marahiel
• Subject Area: Biochemistry
• Term: from 2009 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 152010838

This project is dedicated towards the understanding of the biochemical and structural aspects of tailoring enzymes involved in non-ribosomal peptide synthesis and non-ribosomal peptide synthetases (NRPS), including those who go beyond the classical co-linearity rules. We would like to investigate substrate modifying enzymes associated with Cß-carbon functionalization and piperazic acid synthesis during kutznerides assembly. Furthermore, we will screen bacterial strains containing sequences encoding for interesting NRPSs or modifying enzymes with our well established radio-HPLC-MS detection method (global genome mining approach) to identify novel NRPs produced by Clostridium thermocellum, Herpetosiphon aurantiacus and Saccharopolyspora erythraea. We will start with the biochemical characterization of the biosynthetic assembly line for a cyclic glycosylated sugardipeptide that represents an archetype of a new NRPS product class from C. thermocellum and H. aurantiacus and analyze in parallel a biosynthesis pathway from 5. erythraea for an unusual tryptophan halogenation. In the third part of this proposal we would like to perform intense structural studies on several NRPS modules by employing a new chemical PCPtrapping method utilizing non-hydrolysable amino-Coenzyme A derivatives as well as covalent linkages between catalytic subunits to restrict the domain motion during crystallization.

• DFG Programme: Research Grants