In Vivo Activation of Apo-Hydrogenases Using Synthetic Analogues of the Active Site

Hydrogenases have attracted attention as catalysts for the processing of hydrogen. [FeFe] hydrogenases (HydA) consist of [4Fe4S] cluster directly tethered to an organometallic [2Fe] subsite. The [2Fe] subsite is dependent on a specific subset of maturation enzymes (HydEFG) for its biosynthesis and incorporation into HydA. Synthetic chemistry has made the synthesis of analogues of that subsite possible¹. In this project, [FeFe] hydrogenase from Chlamydomonas reinhardtii was heterologously expressed in the absence of the Hyd-maturation machinery in E. coli BL21. In vivo, biomimetic hydrogen production was achieved upon incubation of the apo-hydA expressing cells with the synthetic mimics of the [2Fe] subsite.  This is the first example of in vivo activation of apo-hydrogenases using synthetic analogues of the active site. The study demonstrates a powerful new tool for activating hydrogenases under in vivo conditions, in the absence of the still only partially characterized maturation machinery.

¹Berggren, G., Adamska, A., Lambertz, C., Simmons, T. R., Esselborn, J., Atta, M., Gambarelli, S., Mouesca, J.M., Reijerse, E., Lubitz, W., Happe, T., Artero, V., Fontecave, M. (2014). Biomimetic assembly and activation of [FeFe] -hydrogenases. Nature, 499(7456), 66–69.