9OQ8

Crystal structure of selenomethionine-substituted cyclodehydratase RohQ

Summary for 9OQ8

Entry DOI	10.2210/pdb9oq8/pdb
Related	9c5w
Descriptor	RohQ, IMIDAZOLE (3 entities in total)
Functional Keywords	azomycin biosynthetic protein, duf6190, cyclodehydratase, de novo emerged enzyme, biosynthetic protein
Biological source	Pseudomonas brassicacearum
Total number of polymer chains	5
Total formula weight	112342.74
Authors	Wei, Z.-W.,Daniel-Ivad, P.,Ryan, K.S. (deposition date: 2025-05-20, release date: 2025-07-23)
Primary citation	Wei, Z.W.,Daniel-Ivad, P.,Zhang, L.,Ryan, K.S. Structure and Mechanism of the Azomycin Biosynthetic Enzyme RohQ That Catalyzes a Spontaneous Cyclodehydration. J.Am.Chem.Soc., 2025 Cited by 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-fold intramolecular cyclization of a guanidino group and aldehyde, releasing water. Our work expands our understanding of emerged enzymes and provides the first structural and mechanistic view of a yet-unexplored protein family. PubMed: 40644315 DOI: 10.1021/jacs.5c04341 PDB entries with the same primary citation
Experimental method	X-RAY DIFFRACTION (2.38 Å)

Structure validation