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From Proteopedia
Crystal structure of human uridine-cytidine kinase 2 complexed with a weak small molecule inhibitor
Structural highlights
FunctionUCK2_HUMAN Phosphorylates uridine and cytidine to uridine monophosphate and cytidine monophosphate. Does not phosphorylate deoxyribonucleosides or purine ribonucleosides. Can use ATP or GTP as a phosphate donor. Can also phosphorylate cytidine and uridine nucleoside analogs such as 6-azauridine, 5-fluorouridine, 4-thiouridine, 5-bromouridine, N(4)-acetylcytidine, N(4)-benzoylcytidine, 5-fluorocytidine, 2-thiocytidine, 5-methylcytidine, and N(4)-anisoylcytidine. Publication Abstract from PubMedPyrimidine nucleotide biosynthesis in humans is a promising chemotherapeutic target for infectious diseases caused by RNA viruses. Because mammalian cells derive pyrimidine ribonucleotides through a combination of de novo biosynthesis and salvage, combined inhibition of dihydroorotate dehydrogenase (DHODH; the first committed step in de novo pyrimidine nucleotide biosynthesis) and uridine/cytidine kinase 2 (UCK2; the first step in salvage of exogenous nucleosides) strongly attenuates viral replication in infected cells. However, while several pharmacologically promising inhibitors of human DHODH are known, to date there are no reports of medicinally viable leads against UCK2. Here, we use structure-based drug prototyping to identify two classes of promising leads that noncompetitively inhibit UCK2 activity. In the process, we have identified a hitherto unknown allosteric site at the intersubunit interface of this homotetrameric enzyme. By reducing the k(cat) of human UCK2 without altering its K(M), these new inhibitors have the potential to enable systematic dialing of the fractional inhibition of pyrimidine salvage to achieve the desired antiviral effect with minimal host toxicity. Structure-Based Prototyping of Allosteric Inhibitors of Human Uridine/Cytidine Kinase 2 (UCK2).,Mashayekh S, Stunkard LM, Kienle M, Mathews II, Khosla C Biochemistry. 2022 Nov 1;61(21):2261-2266. doi: 10.1021/acs.biochem.2c00451. Epub , 2022 Oct 3. PMID:36190114[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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