Molecule of the Month: ZAR1 Resistosome
Plants protect themselves from infection with immune system machines such as the resistosome
Fishing for Pathogens
Pièce de Résistance
Uridylylation Modulation
Exploring the Structure
Resistosome Formation Pathway
Three structures reveal the steps in the process of building the active resistosome. First, a complex composed of the immune receptor ZAR1 (green) bound to ADP (orange) and pseudokinase RSK1 (turquoise) exists in an inactive form inside the plant cell, shown on the left (PDB ID 6j5w). When PBL2 (dark blue) becomes doubly uridylylated, it binds to RSK1 to form the larger intermediate complex depicted in the center (PDB ID 6j5v), allowing it to open up and release ADP. This open, intermediate state is induced by the stabilizing interactions of the two uridylyl groups (magenta) with a loop region of RSK1, which ends up pushing the ATP/ADP-binding domain (light green) away and triggering a conformational change in the ZAR1 structural domain (green). Last, the ZAR1 subunit then binds ATP (orange), leading to additional allosteric conformational changes such as the release of the short alpha helix tail (yellow) and ultimately the formation of the active complex illustrated on the right (PDB ID 6j5t). When five of these activated complexes come together into the complete resistosome assembly, the yellow tails will form the membrane-interacting funnel.
Topics for Further Discussion
- Explore how other organisms make use of macromolecular supercomplexes for regulating immunity and programmed cell death, such as Toll-like receptors and the apoptosome assembly.
- To learn more about computed structure models (CSMs) and how to explore them on RCSB.org, take a look through our documentation pages.
Related PDB-101 Resources
References
- Feng, F., Yang, F., Rong, W., Wu, X., Zhang, J., Chen, S., He, C., Zhou, J.-M. (2012) A Xanthomonas uridine 5′-monophosphate transferase inhibits plant immune kinases. Nature 485: 114–118.
- Wang, G., Roux, B., Feng, F., Guy, E., Li, L. Li, N., Zhang, X., Lautier, M., Jardinaud, M.-F., Chabannes, M., Arlat, M., Chen, S., He, C., Noël, L.D., Zhou, J.-M. (2015) The decoy substrate of a pathogen effector and a pseudokinase specify pathogen-induced modified-self recognition and immunity in plants. Cell Host & Microbe 18: 285–295.
- Burdett, H., Bentham, A.R., Williams, S.J., Dodds, P.N., Anderson, P.A., Banfield, M.J., Kobe, B. (2019) The plant “resistosome”: structural insights into immune signaling. Cell Host & Microbe 26: 193–201.
- Bi, G., Su, M., Li, N., Liang, Y., Dang, S., Xu, J., Hu, M., Wang, J., Zou, M., Deng, Y., Li, Q., Huang, S., Li, J., Chai, J., He, K., Chen, Y.-H., Zhou, J.-M. (2021) The ZAR1 resistosome is a calcium-permeable channel triggering plant immune signaling. Cell 184: 3528–3541.e12.
- 6j5t: Wang, J., Hu, M., Wang, J., Qi, J., Han, Z., Wang, G., Qi, Y., Wang, H.-W., Zhou, J.-M., Chai, J. (2019) Reconstitution and structure of a plant NLR resistosome conferring immunity. Science 364: eaav5870.
- 6j5v, 6j5w: Wang, J., Wang, J., Hu, M., Wu, S., Qi, J., Wang, G., Han, Z., Qi, Y., Gao, N., Wang, H.-W., Zhou, J.-M., Chai, J. (2019) Ligand-triggered allosteric ADP release primes a plant NLR complex. Science 364: eaav5868.
- AF-Q4UWF4-F1: Varadi, M., Anyango, S., Deshpande, M., Nair, S., Natassia, C., Yordanova, G., Yuan, D., Stroe, O., Wood, G., Laydon, A., Žídek, A., Green, T., Tunyasuvunakool, K., Petersen, S., Jumper, J., Clancy, E., Green, R., Vora, A., Lutfi, M., Figurnov, M., Cowie, A., Hobbs, N., Kohli, P., Kleywegt, G., Birney, E., Hassabis, D., Velankar, S. (2022) AlphaFold Protein Structure Database: massively expanding the structural coverage of protein-sequence space with high-accuracy models. Nucleic Acids Research 50: D439–D444.
November 2023, Dennis Piehl, David Goodsell
http://doi.org/10.2210/rcsb_pdb/mom_2023_11