Regulation of cellular levels of ADP-ribose is important in preventing nonenzymatic ADP-ribosylation of proteins. The Escherichia coli ADP-ribose pyrophosphatase, a Nudix enzyme, catalyzes the hydrolysis of ADP-ribose to ribose-5-P and AMP, compounds that can be recycled as part of nucleotide metabolism. The structures of the apo enzyme, the active enzyme and the complex with ADP-ribose were determined to 1.9 A, 2.7 A and 2.3 A, respectively. The structures reveal a symmetric homodimer with two equivalent catalytic sites, each formed by residues of both monomers, requiring dimerization through domain swapping for substrate recognition and catalytic activity. The structures also suggest a role for the residues conserved in each Nudix subfamily. The Nudix motif residues, folded as a loop-helix-loop tailored for pyrophosphate hydrolysis, compose the catalytic center; residues conferring substrate specificity occur in regions of the sequence removed from the Nudix motif. This segregation of catalytic and recognition roles provides versatility to the Nudix family.
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http://dx.doi.org/10.1038/87647 | DOI Listing |
Breast J
January 2025
Department of Thyroid and Breast Surgery, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong 226001, China.
This study aims to investigate the potential causal link between mitochondrial function and breast cancer using the Mendelian randomization (MR) analysis. The data used for this study were obtained from genomewide association studies (GWAS) databases on mitochondrial biological function and breast cancer. Mitochondrial function was considered the exposure variable, breast cancer the outcome variable, and specific single nucleotide polymorphisms (SNPs) were selected as instrumental variables (IVs).
View Article and Find Full Text PDFNat Commun
December 2024
Science for Life Laboratory, Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, SE-141 52, Sweden.
Cellular target engagement technologies enable quantification of intracellular drug binding; however, simultaneous assessment of drug-associated phenotypes has proven challenging. Here, we present cellular target engagement by accumulation of mutant as a platform that can concomitantly evaluate drug-target interactions and phenotypic responses using conditionally stabilized drug biosensors. We observe that drug-responsive proteotypes are prevalent among reported mutants of known drug targets.
View Article and Find Full Text PDFNat Struct Mol Biol
October 2024
Van Andel Institute, Grand Rapids, MI, USA.
Channel enzymes represent a class of ion channels with enzymatic activity directly or indirectly linked to their channel function. We investigated a TRPM2 chanzyme from choanoflagellates that integrates two seemingly incompatible functions into a single peptide: a channel module activated by ADP-ribose with high open probability and an enzyme module (NUDT9-H domain) consuming ADP-ribose at a remarkably slow rate. Using time-resolved cryogenic-electron microscopy, we captured a complete series of structural snapshots of gating and catalytic cycles, revealing the coupling mechanism between channel gating and enzymatic activity.
View Article and Find Full Text PDFSci Bull (Beijing)
September 2024
Department of Biophysics and Department of Neurosurgery, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; GuiZhou University Medical College, Guiyang 550025, China. Electronic address:
Ion channel activation upon ligand gating triggers a myriad of biological events and, therefore, evolution of ligand gating mechanism is of fundamental importance. TRPM2, a typical ancient ion channel, is activated by adenosine diphosphate ribose (ADPR) and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates, but the evolutionary process is still unknown. Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that, the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation, while the N-terminal MHR domain maintains a conserved ligand binding site.
View Article and Find Full Text PDFJ Med Chem
May 2024
Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7FZ, U.K.
Cofactor mimicry represents an attractive strategy for the development of enzyme inhibitors but can lead to off-target effects due to the evolutionary conservation of binding sites across the proteome. Here, we uncover the ADP-ribose (ADPr) hydrolase NUDT5 as an unexpected, noncovalent, off-target of clinical BTK inhibitors. Using a combination of biochemical, biophysical, and intact cell NanoBRET assays as well as X-ray crystallography, we confirm catalytic inhibition and cellular target engagement of NUDT5 and reveal an unusual binding mode that is independent of the reactive acrylamide warhead.
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