Download MendeleyStructural insights into immunoglobulin M.
Li, Y., Wang, G., Li, N., Wang, Y., Zhu, Q., Chu, H., Wu, W., Tan, Y., Yu, F., Su, X.D., Gao, N., Xiao, J.(2020) Science 367: 1014-1017
- PubMed: 32029689
- DOI: https://doi.org/10.1126/science.aaz5425
- Primary Citation of Related Structures:
6KXS - PubMed Abstract:
Immunoglobulin M (IgM) plays a pivotal role in both humoral and mucosal immunity. Its assembly and transport depend on the joining chain (J-chain) and the polymeric immunoglobulin receptor (pIgR), but the underlying molecular mechanisms of these processes are unclear. We report a cryo-electron microscopy structure of the Fc region of human IgM in complex with the J-chain and pIgR ectodomain. The IgM-Fc pentamer is formed asymmetrically, resembling a hexagon with a missing triangle. The tailpieces of IgM-Fc pack into an amyloid-like structure to stabilize the pentamer. The J-chain caps the tailpiece assembly and bridges the interaction between IgM-Fc and the polymeric immunoglobulin receptor, which undergoes a large conformational change to engage the IgM-J complex. These results provide a structural basis for the function of IgM.
Organizational Affiliation:
State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.
