0428同步年報-2021-全

Life Science 049 Fig. 4 : Reaction paths of CD-NTase. (a) The nucleosides are represented with large circles, the phosphate groups with small circles. The donor and acceptor substrate binding sites are indicated with boxes. The nucleophilic attack by the ribose OH group at the α-phosphate is indicated with an arrow. Panels (b) and (c) show the known paths for CDN biosynthesis. Panel (d) shows a possible path that produces CTN with Ec CdnD. [Reproduced from Ref. 5] polymerase-like reactions and conclude with a DncV-like reaction in which the third nucleotide is turned over in the donor site ( Fig. 4 ). In summary, Ec CdnD shares a common architecture of CD- NTases but with significant variations. Two ATP-binding sites were identified in the substrate complex crystals. The donor ATP showed a binding mode similar to that in other NTases, but the acceptor ATP was bound in a reversed direction, indicating a possible inhibitory effect on this Type-II enzyme. By comparison with CDN-producing CD-NTase and RNA polymerase structures, a plausible catalytic path was proposed for CTN synthesis by Ec CdnD. (Reported by Tzu-Ping Ko, Academia Sinica) This report features the work of Yeh Chen and his colleagues published in Nucleic Acids Res. 49 , 4725 (2021). TPS 05A Protein Microcrystallography TLS 15A1 Biopharmaceuticals Protein Crystallography • Protein Crystallography • Biological Macromolecules, Protein Structures, Life Science References 1. W. Zhou, A. T. Whiteley, C. C. de Oliveira Mann, B. R. Morehouse, R. P. Nowak, E. S. Fischer, N. S. Gray, J. J. Mekalanos, P. J. Kranzusch, Cell 174 , 300 (2018). 2. G. B. Severin, M. S. Ramliden, L. A. Hawver, K. Wang, M. E. Pell, A. K. Kieninger, A. Khataokar, B. J. O’Hara, L. V. Behrmann, M. B. Neiditch, C. Benning, C. M. Waters, W. L. Ng, PNAS 115 , E6048 (2018). 3. Q. Ye, R. K. Lau, I. T. Mathews, E. A. Birkholz, J. D. Watrous, C. S. Azimi, J. Pogliano, M. Jain, K. D. Corbett, Mol. Cell 77 , 709 (2020). 4. A. T. Whiteley, J. B. Eaglesham, C. C. de Oliveira Mann, B. R. Morehouse, B. Lowey, E. A. Nieminen, O. Danilchanka, D. S. King, A. S. Y. Lee, J. J. Mekalanos, P. J. Kranzusch, Nature 567 , 194 (2019). 5. T. P. Ko, Y. C. Wang, C. L. Tsai, C. S. Yang, M. H. Hou, Y. Chen, Nucleic Acids Res. 49 , 4725 (2021).