Q81102 · CAPSD_HBVC1
- ProteinCapsid protein
- GeneC
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids183 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
Function
function
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.
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | host cell | |
Cellular Component | host cell cytoplasm | |
Cellular Component | T=4 icosahedral viral capsid | |
Molecular Function | DNA binding | |
Molecular Function | RNA binding | |
Molecular Function | structural molecule activity | |
Biological Process | microtubule-dependent intracellular transport of viral material towards nucleus | |
Biological Process | symbiont entry into host cell | |
Biological Process | viral penetration into host nucleus |
Keywords
- Molecular function
- Biological process
Names & Taxonomy
Protein names
- Recommended nameCapsid protein
- Alternative names
Gene names
Organism names
- Taxonomic lineageViruses > Riboviria > Pararnavirae > Artverviricota > Revtraviricetes > Blubervirales > Hepadnaviridae > Orthohepadnavirus > Hepatitis B virus
- Virus hosts
Accessions
- Primary accessionQ81102
Proteomes
Subcellular Location
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 97 | No effect on capsid stability. | ||||
Sequence: I → L |
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000324363 | 1-183 | Capsid protein | |||
Sequence: MDIDTYKEFGASVELLSFLPSDFFPSIRDLLDTAFALHREALESPEHCSPHHTALRQAIVCWGELMNLATWVGSNLEDPASRELVVSYVNVNMGLKIRQLLWFHISCLTFGRETVLEYLVSVGVWIRTPQAYRPPNAPILSTLPETTVVRRRGRSPRRRTPSPRRRRSKSPRRRRSQSRESQC | ||||||
Modified residue | 155 | Phosphoserine; by host | ||||
Sequence: S | ||||||
Modified residue | 162 | Phosphoserine; by host | ||||
Sequence: S | ||||||
Modified residue | 170 | Phosphoserine; by host | ||||
Sequence: S |
Post-translational modification
Phosphorylated by host SRPK1, SRPK2, and maybe protein kinase C or GAPDH. Phosphorylation is critical for pregenomic RNA packaging. Protein kinase C phosphorylation is stimulated by HBx protein and may play a role in transport of the viral genome to the nucleus at the late step during the viral replication cycle.
Keywords
- PTM
Interaction
Subunit
Homodimerizes, then multimerizes. Interacts with cytosol exposed regions of viral L glycoprotein present in the reticulum-to-Golgi compartment. Interacts with human FLNB. 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.
Family & Domains
Features
Showing features for region, compositional bias, repeat, motif.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 143-183 | Disordered | ||||
Sequence: LPETTVVRRRGRSPRRRTPSPRRRRSKSPRRRRSQSRESQC | ||||||
Compositional bias | 152-174 | Basic residues | ||||
Sequence: RGRSPRRRTPSPRRRRSKSPRRR | ||||||
Repeat | 155-160 | 1; half-length | ||||
Sequence: SPRRRT | ||||||
Region | 155-176 | 3 X 7 AA repeats of S-P-R-R-R-[PR]-S | ||||
Sequence: SPRRRTPSPRRRRSKSPRRRRS | ||||||
Motif | 158-175 | Bipartite nuclear localization signal | ||||
Sequence: RRTPSPRRRRSKSPRRRR | ||||||
Repeat | 162-168 | 2 | ||||
Sequence: SPRRRRS | ||||||
Repeat | 170-176 | 3 | ||||
Sequence: SPRRRRS | ||||||
Region | 177-183 | RNA binding | ||||
Sequence: QSRESQC |
Sequence similarities
Belongs to the orthohepadnavirus core antigen family.
Keywords
- Domain
Family and domain databases
Sequence & Isoform
- Sequence statusComplete
This entry describes 2 isoforms produced by Alternative initiation.
Q81102-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- NameCapsid protein
- Length183
- Mass (Da)21,102
- Last updated1996-11-01 v1
- ChecksumB32B2BF3AF7ED4E8
P0C6H3-1
The sequence of this isoform can be found in the external entry linked below. Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
View isoform- NameExternal core antigen
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 152-174 | Basic residues | ||||
Sequence: RGRSPRRRTPSPRRRRSKSPRRR |
Keywords
- Coding sequence diversity