The two CO-dehydrogenases of Thermococcus sp. AM4.
Benvenuti, M., Meneghello, M., Guendon, C., Jacq-Bailly, A., Jeoung, J.H., Dobbek, H., Leger, C., Fourmond, V., Dementin, S.(2020) Biochim Biophys Acta Bioenerg 1861: 148188-148188
- PubMed: 32209322 
- DOI: https://doi.org/10.1016/j.bbabio.2020.148188
- Primary Citation of Related Structures:  
6T7J - PubMed Abstract: 
Ni-containing CO-dehydrogenases (CODHs) allow some microorganisms to couple ATP synthesis to CO oxidation, or to use either CO or CO 2 as a source of carbon. The recent detailed characterizations of some of them have evidenced a great diversity in terms of catalytic properties and resistance to O 2 . In an effort to increase the number of available CODHs, we have heterologously produced in Desulfovibrio fructosovorans, purified and characterized the two CooS-type CODHs (CooS1 and CooS2) from the hyperthermophilic archaeon Thermococcus sp. AM4 (Tc). We have also crystallized CooS2, which is coupled in vivo to a hydrogenase. CooS1 and CooS2 are homodimers, and harbour five metalloclusters: two [Ni4Fe-4S] C clusters, two [4Fe-4S] B clusters and one interfacial [4Fe-4S] D cluster. We show that both are dependent on a maturase, CooC1 or CooC2, which is interchangeable. The homologous protein CooC3 does not allow Ni insertion in either CooS. The two CODHs from Tc have similar properties: they can both oxidize and produce CO. The Michaelis constants (K m ) are in the microM range for CO and in the mM range (CODH 1) or above (CODH 2) for CO 2 . Product inhibition is observed only for CO 2 reduction, consistent with CO 2 binding being much weaker than CO binding. The two enzymes are rather O 2 sensitive (similarly to CODH II from Carboxydothermus hydrogenoformans), and react more slowly with O 2 than any other CODH for which these data are available.
Organizational Affiliation: 
Aix-Marseille Université, CNRS, BIP UMR 7281, 31 Chemin J. AIGUIER, CS70071, F-13402 Marseille Cedex 20, (France).