Mes compétences :
Protein Purification
Protein expression
Enzymology
Polymerase Chain Reaction
Microbiology
Biotechnology
Molecular biology
Electrochemistry
Biochemistry
Entreprises
CNRS
- PhD student
Paris2012 - maintenantSome microorganisms use Carbon Monoxide Dehydrogenase (CODH) to catalyse the reversible oxidation of CO into CO2 according to the reaction: CO2+ 2H+ +2e- ↔ CO + H2O. The Nickel-Iron (Ni-Fe) CODHs are found in some anaerobic organisms such as Carboxydothermus hydrogenoformans or the photosynthetic bacterium Rhodospirullum rubrum which use CO as sole energy source. This is probably due to the involvement of CODHs in the generation of a proton motive force in association with hydrogenases. In some cases, CODHs are involved in CO2 fixation, in association with an Acetyl-CoA synthase. The precise role of the CODH from our model organism, Desulfovibrio vulgaris (Dv), is still unclear.
The biosynthesis of the active site of Ni-Fe CODHs requires at least one accessory protein in R. rubrum and C. hydrogenoformans. In particular, it is believed that the CooC protein favors the insertion of Ni in the active site (1,2). We have developed a system allowing the production of the Dv CODH in the presence or absence of its accessory protein CooC to determine the biochemical, kinetic and structural properties of biosynthetic intermediates of the Ni-Fe active site.
Furthermore, there is some controversy in literature about the active site’s structure (3-5). On the basis of crystallographic investigations, several research groups have determined different active site structures, some of which would not be involved in catalytic cycle. Protein film voltammetry studies in our laboratory have revealed unprecedented kinetic properties of the Dv enzyme that shed new light on the structural heterogeneity observed by crystallography and may question the catalytic mechanisms proposed on the basis of these structures.
1. Jeon and al. (2001) J Biol Chem 276, 38602-38609
2. Jeoung and al. (2010) J Mol Biol 396, 1165-1179
3. Dobbek and al. (2001) Science 293, 1281-1285
4. Drennan and al (2001) Proc Natl Acad Sci U S A 98, 11973-11978
5. Jeoung and al. (2007) Science 318, 1461-1464
