Q9QMI2 (CAPSD_HBVD4) Reviewed, UniProtKB/Swiss-Prot
Last modified
May 31, 2011.
Version 44.
History...
Clusters with 
Names·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize orderNames·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize orderNames and origin
| Protein names | Recommended name: Capsid protein Alternative name(s): Core antigen Core protein HBcAg p21.5 | ||
| Gene names |
| ||
| Organism | Hepatitis B virus genotype D subtype ayw (isolate Japan/JYW796/1988) (HBV-D) [Complete proteome] | ||
| Taxonomic identifier | 489487 [NCBI] | ||
| Taxonomic lineage | Viruses › Retro-transcribing viruses › Hepadnaviridae › Orthohepadnavirus | ||
| Virus host | Pan troglodytes (Chimpanzee) [TaxID: 9598] Homo sapiens (Human) [TaxID: 9606] |
Protein attributes
| Sequence length | 183 AA. |
| Sequence status | Complete. |
| Protein existence | Inferred from homology |
General annotation (Comments)
| Function | Self assembles to form an icosahedral capsid. Most capsid appear to be large particles with a 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 capsid 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 stucked 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 genome for transcription, or bud through the endoplasmic reticulum to provide new virions By similarity. Encapsidates hepatitis delta genome By similarity. |
| Subunit structure | Homodimerizes, then multimerizes. Interacts with cytosol exposed regions of viral L glycoprotein present in the reticulum-to-Golgi compartment. Interacts with human FLNB By similarity. |
| Subcellular location | Capsid protein: Virion. Host cytoplasm By similarity. |
| Post-translational modification | Phosphorylated by host SRPK1, SRPK2, and maybe protein kinase A, 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 viral replication cycle. Protein kinase A phosphorylation may promote capsid assembly By similarity. |
| Sequence similarities | Belongs to the orthohepadnavirus core antigen family. |
Ontologies
Alternative products
| This entry describes 2 isoforms produced by alternative initiation. [Align] [Select] | ||||||
| Isoform Capsid protein (identifier: Q9QMI2-1) 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. | ||||||
| Isoform External core antigen (identifier: P0C6I0-1) The sequence of this isoform can be found in the external entry P0C6I0. Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly. |
Sequence annotation (Features)
| Feature key | Position(s) | Length | Description | Graphical view | Feature identifier | ||||
Molecule processing | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Chain | 1 – 183 | 183 | Capsid protein | PRO_0000324370 | |||||
Regions | |||||||||
| Repeat | 155 – 161 | 7 | 1; half-length | ||||||
| Repeat | 162 – 169 | 8 | 2 | ||||||
| Repeat | 170 – 177 | 8 | 3 | ||||||
| Region | 155 – 177 | 23 | 3 X 8 AA repeats of S-P-R-R-R-[PR]-S-Q | ||||||
| Region | 177 – 183 | 7 | RNA binding By similarity | ||||||
| Motif | 158 – 175 | 18 | Bipartite nuclear localization signal Potential | ||||||
Amino acid modifications | |||||||||
| Modified residue | 87 | 1 | Phosphoserine; by host PKA By similarity | ||||||
| Modified residue | 155 | 1 | Phosphoserine; by host By similarity | ||||||
| Modified residue | 162 | 1 | Phosphoserine; by host By similarity | ||||||
| Modified residue | 170 | 1 | Phosphoserine; by host By similarity | ||||||
Sequences
| ||||||||||||||||||||||||
References
| [1] | "Typing hepatitis B virus by homology in nucleotide sequence: comparison of surface antigen subtypes." Okamoto H., Tsuda F., Sakugawa H., Sastrosoewignjo R.I., Imai M., Miyakawa Y., Mayumi M. J. Gen. Virol. 69:2575-2583(1988) [PubMed: 3171552] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. |
| + | Additional computationally mapped references. |
Web resources
| HepSEQ Hepatitis virus B database |
Cross-references
Sequence databases | |
|---|---|
| EMBL GenBank DDBJ | AB033558 Genomic DNA. Translation: BAA85372.1. |
3D structure databases | |
| ProteinModelPortal | Q9QMI2. |
| SMR | Q9QMI2. Positions 1-148. |
| ModBase | Search... |
Protocols and materials databases | |
| StructuralBiologyKnowledgebase | Search... |
Family and domain databases | |
| InterPro | IPR002006. Viral_capsid_core_Hepatitis. [Graphical view] |
| Pfam | PF00906. Hepatitis_core. 1 hit. [Graphical view] |
| SUPFAM | SSF47852. Viral_capsid_core_Hepatitis. 1 hit. |
| ProtoNet | Search... |
Entry information
| Entry name | CAPSD_HBVD4 | ||||||||
| Accession | Primary (citable) accession number: Q9QMI2 | ||||||||
| Entry history |
| ||||||||
| Entry status | Reviewed (UniProtKB/Swiss-Prot) | ||||||||
| Annotation program | Viral Protein Annotation Program | ||||||||
Relevant documents
| SIMILARITY comments Index of protein domains and families |