Unlocking structural biology to enzymes from non-cultivable microbes by a native shotgun approach

The vast majority of microbes cannot be isolated, hindering the biochemical characterization of their enzymes, harboring native cofactors, post-translational
modifications, and physiological partners that can be overlooked when employing recombinant systems. These enzymes represent a treasure trove of catalysts that
could be potentially applied for biomimicry to industrial applications. Here, we propose an alternative approach to bypass the microbial isolation barrier and the bias
of recombinant expression by directly characterizing enzymes from complex microbial communities. In other words, we will anaerobically purify enzymes involved
in transforming one-unit carbon (C1) from microbial enrichment, bioreactors, or even sludge. As a proof of concept, we isolated, crystallized, and structurally
characterized the methane-generating enzyme from an activated wastewater treatment plant sludge. Future results will sharpen our view on C1-metabolism and their
enzymatic mechanistics.