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Crystal structure of human CD38 extracellular domain, ribose-5'-phosphate intermediate/GTP complexCrystal structure of human CD38 extracellular domain, ribose-5'-phosphate intermediate/GTP complex
Structural highlights
FunctionCD38_HUMAN Synthesizes cyclic ADP-ribose, a second messenger for glucose-induced insulin secretion. Also has cADPr hydrolase activity. Also moonlights as a receptor in cells of the immune system. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedEnzymatic utilization of nicotinamide adenine dinucleotide (NAD) has increasingly been shown to have fundamental roles in gene regulation, signal transduction, and protein modification. Many of the processes require the cleavage of the nicotinamide moiety from the substrate and the formation of a reactive intermediate. Using X-ray crystallography, we show that human CD38, an NAD-utilizing enzyme, is capable of catalyzing the cleavage reactions through both covalent and noncovalent intermediates, depending on the substrate used. The covalent intermediate is resistant to further attack by nucleophiles, resulting in mechanism-based enzyme inactivation. The noncovalent intermediate is stabilized mainly through H-bond interactions, but appears to remain reactive. Our structural results favor the proposal of a noncovalent intermediate during normal enzymatic utilization of NAD by human CD38 and provide structural insights into the design of covalent and noncovalent inhibitors targeting NAD-utilization pathways. Covalent and noncovalent intermediates of an NAD utilizing enzyme, human CD38.,Liu Q, Kriksunov IA, Jiang H, Graeff R, Lin H, Lee HC, Hao Q Chem Biol. 2008 Oct 20;15(10):1068-78. PMID:18940667[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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