From the research article:<p>> <i>Catalytic H2 production by NB-2Ni was demonstrated using a photochemical assay with an organic dye (EosinY) as a photosensitizer and triethanolamine (TEOA) as a sacrificial electron donor irradiated at 540 nm (15).</i><p>IIUC the main reaction is<p>2 H+ + TEOA + light --> H2 + ???<p>so they store the energy of the light in the H2, and assume that the cell already know how to use the H2.<p>The TEOA is slightly oxidized to ???. It has a few alcohol groups that are good candidates to be transformed.<p>The reaction also uses a dye, that is probably responsible to capture the light initially, and then transfer the energy to the enzyme.<p>It's also interesting because it's very small, only 13 amino acids. Many modern proteins have hundreds of amino acids that makes a brute force search approach to find them very difficult, but with 13 the search space is only ~ 20^13.