UniProtKB - P03148 (CAPSD_HBVA3)
Capsid protein
C
Functioni
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.
UniRule annotationGO - Molecular functioni
- DNA binding Source: UniProtKB-UniRule
- RNA binding Source: UniProtKB-UniRule
- structural molecule activity Source: UniProtKB-UniRule
GO - Biological processi
- microtubule-dependent intracellular transport of viral material towards nucleus Source: UniProtKB-UniRule
- viral entry into host cell Source: UniProtKB-UniRule
- viral penetration into host nucleus Source: UniProtKB-UniRule
Keywordsi
Molecular function | DNA-binding, RNA-binding |
Biological process | Cytoplasmic inwards viral transport, Host-virus interaction, Microtubular inwards viral transport, Viral penetration into host nucleus, Virus entry into host cell |
Names & Taxonomyi
Protein namesi | Recommended name: Capsid proteinUniRule annotationAlternative name(s): Core antigenUniRule annotation Core proteinUniRule annotation HBcAgUniRule annotation p21.5UniRule annotation |
Gene namesi | Name:CUniRule annotation |
Organismi | Hepatitis B virus genotype A2 subtype adw2 (strain Rutter 1979) (HBV-A) |
Taxonomic identifieri | 480116 [NCBI] |
Taxonomic lineagei | Viruses › Riboviria › Pararnavirae › Artverviricota › Revtraviricetes › Blubervirales › Hepadnaviridae › Orthohepadnavirus › |
Virus hosti | Homo sapiens (Human) [TaxID: 9606] Pan troglodytes (Chimpanzee) [TaxID: 9598] |
Proteomesi |
|
Subcellular locationi
- Virion UniRule annotation1 Publication
- Host cytoplasm UniRule annotation1 Publication
Keywords - Cellular componenti
Capsid protein, Host cytoplasm, T=4 icosahedral capsid protein, VirionPathology & Biotechi
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 48 | C → A: No effect on dimer or capsid formation. 1 Publication | 1 | |
Mutagenesisi | 61 | C → A: No effect on dimer or capsid formation. 1 Publication | 1 | |
Mutagenesisi | 107 | C → A: No effect on dimer or capsid formation. 1 Publication | 1 | |
Mutagenesisi | 157 | S → A: Increases nuclear localization. 1 Publication | 1 | |
Mutagenesisi | 164 | S → A: Increases nuclear localization. 1 Publication | 1 | |
Mutagenesisi | 172 | S → A: Increases nuclear localization. 1 Publication | 1 | |
Mutagenesisi | 185 | C → A: No effect on dimer or capsid formation. 1 Publication | 1 |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
ChainiPRO_0000222308 | 1 – 185 | Capsid proteinAdd BLAST | 185 |
Amino acid modifications
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Modified residuei | 157 | Phosphoserine; by hostUniRule annotation1 Publication | 1 | |
Modified residuei | 164 | Phosphoserine; by hostUniRule annotation1 Publication | 1 | |
Modified residuei | 172 | Phosphoserine; by hostUniRule annotation1 Publication | 1 |
Post-translational modificationi
Keywords - PTMi
PhosphoproteinPTM databases
iPTMneti | P03148 |
Interactioni
Subunit structurei
Homodimerizes, then multimerizes.
Interacts with cytosol exposed regions of viral L glycoprotein present in the reticulum-to-Golgi compartment (PubMed:31700077).
Interacts with human FLNB (PubMed:10754391). Phosphorylated form interacts with host importin alpha; this interaction depends on the exposure of the NLS, which itself depends upon genome maturation and/or phosphorylation of the capsid protein.
Interacts with host NUP153.
UniRule annotation2 PublicationsFamily & Domainsi
Domains and Repeats
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Repeati | 157 – 163 | 1; half-length | 7 | |
Repeati | 164 – 171 | 2 | 8 | |
Repeati | 172 – 179 | 3 | 8 |
Region
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Regioni | 136 – 185 | DisorderedSequence analysisAdd BLAST | 50 | |
Regioni | 157 – 179 | 3 X 8 AA repeats of S-P-R-R-R-[PR]-S-QAdd BLAST | 23 | |
Regioni | 179 – 185 | RNA bindingUniRule annotation | 7 |
Motif
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Motifi | 160 – 177 | Bipartite nuclear localization signalUniRule annotationAdd BLAST | 18 |
Compositional bias
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Compositional biasi | 153 – 175 | Basic residuesSequence analysisAdd BLAST | 23 |
Sequence similaritiesi
Keywords - Domaini
RepeatFamily and domain databases
Gene3Di | 1.10.4090.10, 1 hit |
HAMAPi | MF_04076, HBV_HBEAG, 1 hit |
InterProi | View protein in InterPro IPR002006, Hepatitis_core IPR036459, Viral_capsid_core_dom_sf_HBV |
Pfami | View protein in Pfam PF00906, Hepatitis_core, 3 hits |
SUPFAMi | SSF47852, SSF47852, 1 hit |
s (2)i Sequence
Sequence statusi: Complete.
This entry describes 2 produced by isoformsialternative initiation. AlignAdd to basketThis isoform has been chosen as the sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry. canonicali
10 20 30 40 50
MDIDPYKEFG ATVELLSFLP SDFFPSVRDL LDTASALYRE ALESPEHCSP
60 70 80 90 100
HHTALRQAIL CWGELMTLAT WVGNNLEDPA SRDLVVNYVN TNVGLKIRQL
110 120 130 140 150
LWFHISCLTF GRETVLEYLV SFGVWIRTPP AYRPPNAPIL STLPETTVVR
160 170 180
RRDRGRSPRR RTPSPRRRRS PSPRRRRSQS RESQC
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
Natural variant
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Natural varianti | 93 | V → M. | 1 | |
Natural varianti | 97 | I → L Frequent mutation in chronic HBV carriers. 1 Publication | 1 | |
Natural varianti | 169 | R → P. | 1 |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | X02763 Genomic DNA Translation: CAA26537.1 |
Keywords - Coding sequence diversityi
Alternative initiationSimilar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | X02763 Genomic DNA Translation: CAA26537.1 |
3D structure databases
SMRi | P03148 |
ModBasei | Search... |
PTM databases
iPTMneti | P03148 |
Family and domain databases
Gene3Di | 1.10.4090.10, 1 hit |
HAMAPi | MF_04076, HBV_HBEAG, 1 hit |
InterProi | View protein in InterPro IPR002006, Hepatitis_core IPR036459, Viral_capsid_core_dom_sf_HBV |
Pfami | View protein in Pfam PF00906, Hepatitis_core, 3 hits |
SUPFAMi | SSF47852, SSF47852, 1 hit |
MobiDBi | Search... |
Entry informationi
Entry namei | CAPSD_HBVA3 | |
Accessioni | P03148Primary (citable) accession number: P03148 Secondary accession number(s): Q67868 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | July 21, 1986 |
Last sequence update: | January 15, 2008 | |
Last modified: | September 29, 2021 | |
This is version 91 of the entry and version 3 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Viral Protein Annotation Program |