6ilj

Cryo-EM structure of Echovirus 6 complexed with its attachment receptor CD55 at PH 5.5Cryo-EM structure of Echovirus 6 complexed with its attachment receptor CD55 at PH 5.5

6ilj, resolution 3.60Å Show:Asymmetric Unit Biological Assembly Structural highlights 6ilj is a 5 chain structure with sequence from Echovirus e6 and Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Gene: CD55, CR, DAF (HUMAN) Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [DAF_HUMAN] This protein recognizes C4b and C3b fragments that condense with cell-surface hydroxyl or amino groups when nascent C4b and C3b are locally generated during C4 and c3 activation. Interaction of daf with cell-associated C4b and C3b polypeptides interferes with their ability to catalyze the conversion of C2 and factor B to enzymatically active C2a and Bb and thereby prevents the formation of C4b2a and C3bBb, the amplification convertases of the complement cascade. Publication Abstract from PubMed Enterovirus B (EV-B), a major proportion of the genus Enterovirus in the family Picornaviridae, is the causative agent of severe human infectious diseases. Although cellular receptors for coxsackievirus B in EV-B have been identified, receptors mediating virus entry, especially the uncoating process of echovirus and other EV-B remain obscure. Here, we found that human neonatal Fc receptor (FcRn) is the uncoating receptor for major EV-B. FcRn binds to the virus particles in the "canyon" through its FCGRT subunit. By obtaining multiple cryo-electron microscopy structures at different stages of virus entry at atomic or near-atomic resolution, we deciphered the underlying mechanisms of enterovirus attachment and uncoating. These structures revealed that different from the attachment receptor CD55, binding of FcRn to the virions induces efficient release of "pocket factor" under acidic conditions and initiates the conformational changes in viral particle, providing a structural basis for understanding the mechanisms of enterovirus entry. Human Neonatal Fc Receptor Is the Cellular Uncoating Receptor for Enterovirus B.,Zhao X, Zhang G, Liu S, Chen X, Peng R, Dai L, Qu X, Li S, Song H, Gao Z, Yuan P, Liu Z, Li C, Shang Z, Li Y, Zhang M, Qi J, Wang H, Du N, Wu Y, Bi Y, Gao S, Shi Y, Yan J, Zhang Y, Xie Z, Wei W, Gao GF Cell. 2019 May 30;177(6):1553-1565.e16. doi: 10.1016/j.cell.2019.04.035. Epub, 2019 May 16. PMID:31104841 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.