| Literature DB >> 32029689 |
Yaxin Li1,2, Guopeng Wang3, Ningning Li2,3, Yuxin Wang1,2, Qinyu Zhu1,2, Huarui Chu1,2, Wenjun Wu4,5, Ying Tan4,5, Feng Yu4,5,6, Xiao-Dong Su1, Ning Gao2,3, Junyu Xiao7,2.
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.Entities:
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Year: 2020 PMID： 32029689 DOI： 10.1126/science.aaz5425
Source DB: PubMed Journal: Science ISSN： 0036-8075 Impact factor: 47.728