Project Details
Projekt
Functional and structural characterization of the Se-Mo active site in CO dehydrogenase
Applicant
Professor Dr. Ortwin Meyer
Subject Area
Biochemistry
Term
from 2000 to 2005
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 5241572
Carbon monoxide (CO)dehydrogenase of Oligotropha carboxidovorans is a selenium containing molybdo iron-sulfur flavoprotein. Recently, we have solved the high resolution structure of the air-oxidized enzyme. The active site structure shows an unprecedented [Cu-S-Mo] cluster, which is bound by the two thiolates of molybdopterin-cytosine-dinucleotide and the g-sulfur of the amino acid Cys388. Frequently, catalytically incompetent enzyme species with an incomplete reaction center are synthesized in vivo, especially, if the posttranslational biosynthesis of the [Cu-S-Mo] cluster is slower than protein biosynthesis. This CO dehydrogenase species react in vitro with selenite by covalent incorporation of selenium and reactivation. In this project, we will characterize the function of selenium in the selenium modified enzyme species. This will be checked by studying the reactions and structures of the wild-type enzyme as well as of the selenium modified enzyme species by protein crystallography, along with electron paramagnetic resonance (EPR) spectroscopy, extended X-ray absorption fine structure (EXAFS) and 75Se incorporation/release experiments.
DFG Programme
Priority Programmes
