Structural highlights
FunctionURDA_SHEON Catalyzes the two-electron reduction of urocanate to dihydrourocanate (also named imidazole propionate or deamino-histidine). The physiological electron donor is unknown; it might be the membrane-bound tetraheme cytochrome c (CymA). Enables anaerobic growth with urocanate as a sole terminal electron acceptor, and thus can provide the cells with a niche where no other bacteria can compete and survive. Is unable to reduce cinnamate and other unsaturated organic acids such as acrylic, crotonic, fumaric and orotic acids. Has no fumarate reductase or succinate dehydrogenase activity.[1] Publication Abstract from PubMedUrocanate reductase (UrdA) is a bacterial enzyme that converts urocanic acid to imidazole propionate. Its catalytic residue Arg411 undergoes a large conformational change in the substrate-bound versus product-bound states. In contrast to previously studied cryo-conditions, the room-temperature X-ray data of UrdA presented here show that the occupancy distribution of Arg411 is affected by crystal cryocooling. We further provide evidence that a phosphate ion stabilizes the substrate complex and can bias the conformation of Arg411. Both room-temperature and cryogenic X-ray datasets were essential to elucidate the dynamic nature of the UrdA active site, highlighting the importance of collecting data at both temperatures, as each may reveal distinct conformational states. Structural insights into urocanate reductase using room-temperature X-ray crystallography.,Aggarwal S, Gurav N, Oksanen E, Lindkvist-Petersson K, Venskutonyte R Acta Crystallogr D Struct Biol. 2026 Jun 1. doi: 10.1107/S2059798326003360. PMID:42083916[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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This page was last modified 11:47, 24 May 2026.