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

Authors: 
Khanna, N., Uppsala University
Meszaros, L., Uppsala University
Esmieu, C., Uppsala University
Berggren, G., Uppsala University
Lindblad, P., Uppsala University

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.