X-ray structure analyses of 4-hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum and possible complexes with substrate, product as well as substrate and product analogues

• Applicant: Privatdozent Dr. Albrecht Messerschmidt
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2000 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5273084

The goal of this grant application is the determination of the X-ray crystal structure of 4-hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum. As 4-hydroxybutyryl-CoA dehydratase contains iron/sulfur clusters the multiple wavelength anomalous dispersion (MAD) technique can be applied which forms the basis for a straightforward X-ray structure analysis. The crystallization of the enzyme will be performed under anaerobic conditions. The knowledge if the three-dimensional atomic structure of this flavin-iron/sulfur enzyme will form the rational basis for understanding the mechanistic action of this peculiar enzyme, a better interpretation of the spectroscopic and kinetic data and the planning of new advancing experiments (e.g. site-directed mutagenesis, crystal structures of substrate analogue/enzyme or inhibitor/enzyme complexes). The key point of interest is the clarification if really during catalysis selective radical intermediates are generated in the enzyme. Furthermore, the structure determination will prove if the Fe-S clusters are close to each other and to the FAD group allowing the spectroscopic coupling of the Fe-S clusters and the interaction between the Fe-S clusters and the FAS group.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1071: Radikale in der enzymatischen Katalyse