The two CO-dehydrogenases of Thermococcus sp. AM4

Martino Benvenuti (1) , Marta Meneghello (1) , Chloé Guendon (1) , Aurore Jacq-Bailly (1) , Jae-Hun Jeoung (2) , Holger Dobbek (2) , Christophe Léger (1) , Vincent Fourmond (1) , Sébastien Dementin (1)

1 BIP - Bioénergétique et Ingénierie des Protéines
2 HU Berlin - Humboldt-Universität zu Berlin = Humboldt University of Berlin = Université Humboldt de Berlin

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 has 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 NiFe 4 S 4 C clusters, two [4Fe4S] B clusters and one interfacial [4Fe4S] 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.

Mots clés: metalloenzyme maturation; metalloenzyme; crystal structure; protein film voltammetry; Ni-containing carbon monoxide dehydrogenase

Domaines: Biochimie, Biologie Moléculaire; Chimie

Martino Benvenuti, Marta Meneghello, Chloé Guendon, Aurore Jacq-Bailly, Jae-Hun Jeoung, et al.. The two CO-dehydrogenases of Thermococcus sp. AM4. Biochimica biophysica acta (BBA) - Bioenergetics, 2020, pp.148188. ⟨10.1016/j.bbabio.2020.148188⟩. ⟨hal-02537797⟩