The covalent insertion of a Cobalt heme into the cavity of an artificial protein named alpha Rep (aRep) leads to an artificial cobalt hemoprotein that is active as a catalyst not only for the photoinduced production of H2 but also for the reduction of CO2 in a neutral aqueous solution. This new artificial metalloenzyme has been purified and characterized by Maldi-TOF MS, circular dichroism and UV-visible spectroscopy. Using theoretical experiments, the structure of this biohybrid and the positioning of the residues near the metal complex were examined, which made it possible to complete the coordination of the cobalt ion by an axial glutamine Gln283 ligand. While the Co(III)porphyrin catalyst alone showed a weak catalytic activity for both reactions, 10 times more H2 and 4 times more CO2 were produced when the Co(III)-porphyrin complex was buried in the hydrophobic cavity of the protein. This study thus provides a solid basis for further improvement of these biohybrids, using well-designed modifications of the second and outer coordination sphere, by site-directed mutagenesis of the host protein.