Structure and Mechanism of the Azomycin Biosynthetic Enzyme RohQ That Catalyzes a Spontaneous Cyclodehydration.
Wei, Z.W., Daniel-Ivad, P., Zhang, L., Ryan, K.S.(2025) J Am Chem Soc 147: 25117-25122
- PubMed: 40644315 
- DOI: https://doi.org/10.1021/jacs.5c04341
- Primary Citation of Related Structures:  
9C5W, 9OQ8 - PubMed Abstract: 
RohQ from the azomycin biosynthetic pathway catalyzes a spontaneous cyclodehydration to form 2-aminoimidazole. Here we report the structure and mechanism of RohQ and use a serendipitously bound imidazole to pinpoint active site residues. We propose that catalysis occurs at the dimeric interface using two key aspartic acid residues for proton transfer steps to accelerate 3 × 10 4 -fold intramolecular cyclization of a guanidino group and aldehyde, releasing water. Our work expands our understanding of de novo emerged enzymes and provides the first structural and mechanistic view of a yet-unexplored protein family.
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Organizational Affiliation: 
















