7abl

HBV pgRNA T=4 NCP icosahedral symmetryHBV pgRNA T=4 NCP icosahedral symmetry

Structural highlights 7abl is a 4 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [Q765V7_HBV] 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.[RuleBase:RU361253] Self assembles to form an icosahedral capsid. Most capsids appear to be large particles with an icosahedral symmetry of T=4 and consist of 240 copies of capsid protein, though a fraction forms smaller T=3 particles consisting of 180 capsid proteins. Entering capsids are transported along microtubules to the nucleus. Phosphorylation of the capsid is thought to induce exposure of nuclear localization signal in the C-terminal portion of the capsid protein that allows binding to the nuclear pore complex via the importin (karyopherin-) alpha and beta. Capsids are imported in intact form through the nuclear pore into the nuclear basket, where it probably binds NUP153. Only capsids that contain the mature viral genome can release the viral DNA and capsid protein into the nucleoplasm. Immature capsids get stuck in the basket. Capsids encapsulate the pre-genomic RNA and the P protein. Pre-genomic RNA is reverse-transcribed into DNA while the capsid is still in the cytoplasm. The capsid can then either be directed to the nucleus, providing more genomes for transcription, or bud through the endoplasmic reticulum to provide new virions.[HAMAP-Rule:MF_04076] Publication Abstract from PubMed The roles of RNA sequence/structure motifs, Packaging Signals (PSs), for regulating assembly of an HBV genome transcript have been investigated in an efficient in vitro assay containing only core protein (Cp) and RNA. Variants of three conserved PSs, within the genome of a strain not used previously, preventing correct presentation of a Cp-recognition loop motif are differentially deleterious for assembly of nucleocapsid-like particles (NCPs). Cryo-electron microscopy reconstruction of the T = 4 NCPs formed with the wild-type gRNA transcript, reveal that the interior of the Cp shell is in contact with lower resolution density, potentially encompassing the arginine-rich protein domains and gRNA. Symmetry relaxation followed by asymmetric reconstruction reveal that such contacts are made at every symmetry axis. We infer from their regulation of assembly that some of these contacts would involve gRNA PSs, and confirmed this by X-ray RNA footprinting. Mutation of the epsilon stem-loop in the gRNA, where polymerase binds in vivo, produces a poor RNA assembly substrate with Cp alone, largely due to alterations in its conformation. The results show that RNA PSs regulate assembly of HBV genomic transcripts in vitro, and therefore may play similar roles in vivo, in concert with other molecular factors. In vitro functional analysis of gRNA sites regulating assembly of hepatitis B virus.,Patel N, Clark S, Weiss EU, Mata CP, Bohon J, Farquhar ER, Maskell DP, Ranson NA, Twarock R, Stockley PG Commun Biol. 2021 Dec 16;4(1):1407. doi: 10.1038/s42003-021-02897-2. PMID:34916604 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 7abl, resolution 3.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image