8ber
From Proteopedia
Hepatitis B virus core antigen (HBc) with the insertion of four external domains of the influenza A M2 protein (HBc/4M2e) with T=3 topology
Structural highlights
FunctionM2_I54A2 Forms a proton-selective ion channel that is necessary for the efficient release of the viral genome during virus entry. After attaching to the cell surface, the virion enters the cell by endocytosis. Acidification of the endosome triggers M2 ion channel activity. The influx of protons into virion interior is believed to disrupt interactions between the viral ribonucleoprotein (RNP), matrix protein 1 (M1), and lipid bilayers, thereby freeing the viral genome from interaction with viral proteins and enabling RNA segments to migrate to the host cell nucleus, where influenza virus RNA transcription and replication occur. Also plays a role in viral proteins secretory pathway. Elevates the intravesicular pH of normally acidic compartments, such as trans-Golgi network, preventing newly formed hemagglutinin from premature switching to the fusion-active conformation.[HAMAP-Rule:MF_04069]HBEAG_HBVD3 May regulate immune response to the intracellular capsid in acting as a T-cell tolerogen, by having an immunoregulatory effect which prevents destruction of infected cells by cytotoxic T-cells. This immune regulation may predispose to chronicity during perinatal infections and prevent severe liver injury during adult infections.[HAMAP-Rule:MF_04076]Q9E0P3_HBV Publication Abstract from PubMedHepatitis B virus core antigen (HBc) with the insertion of four external domains of the influenza A M2 protein (HBc/4M2e) form virus-like particles whose structure was studied using a combination of molecular modeling and cryo-electron microscopy (cryo-EM). It was also shown that self-assembling of the particles occurs inside bacterial cells, but despite the big inner volume of the core shell particle, purified HBc/4M2e contain an insignificant amount of bacterial proteins. It was shown that a fragment of the M2e corresponding to 4M2e insertion is prone to formation of amyloid-like fibrils. However, as the part of the immunodominant loop, M2e insertion does not show a tendency to intermolecular interaction. A full-atomic HBc-4M2e model with the resolution of about 3 A (3.13 A for particles of capital TE, Cyrillic = 4 symmetry, 3.7 A for particles of capital TE, Cyrillic = 3 symmetry) was obtained by molecular modeling methods based on cryo-EM data. Inside and outside of virus-like particles HBc and HBc/4M2e: A comprehensive study of the structure.,Egorov VV, Shvetsov AV, Pichkur EB, Shaldzhyan AA, Zabrodskaya YA, Vinogradova DS, Nekrasov PA, Gorshkov AN, Garmay YP, Kovaleva AA, Stepanova LA, Tsybalova LM, Shtam TA, Myasnikov AG, Konevega AL Biophys Chem. 2022 Dec 5;293:106943. doi: 10.1016/j.bpc.2022.106943. PMID:36495688[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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