P08383 · BM2_INBSI
- ProteinMatrix protein 2
- GeneM
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids109 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
Forms presumably a highly low-pH gated proton-selective channel. Trp-23 may function as a minimalistic gate that opens and closes the pore. When the environmental pH is lower than a threshold, the BM2 channel would be activated and selectively transport protons across the membrane from the extracellular side to the cytoplasmic side. Crucial for the uncoating process. When the virion is internalized into the endosome, the channel acidifies the virion's interior, promoting the dissociation of matrix protein 1 (M1) from the ribonucleoprotein (RNP) thus allowing the transport of the RNP from the virion into the cell's nucleus. Also plays a role in viral protein 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 (By similarity).
Plays a crucial role in virion assembly. Expressed in the late phase of the infection (By similarity).
Plays a crucial role in virion assembly. Expressed in the late phase of the infection (By similarity).
Miscellaneous
Influenza B virus genome RNA segment 7 encodes the M1 (AC P06816) and BM2 proteins. Normal translation produces the M1 protein. The M1 termination codon overlaps the BM2 initiation codon in an overlapping stop-start pentanucleotide 5'-UAAUG-3'. Termination of M1 translation triggers reinitiation on the BM2 AUG in the +2 open reading frame.
Features
Showing features for site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Site | 19 | Essential for channel activity, possibly by being protonated during channel activation, and by forming the channel gate and the selective filter | |||
Site | 23 | Seems to be involved in pH gating | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | host cell plasma membrane | |
Cellular Component | membrane | |
Cellular Component | virion membrane | |
Molecular Function | channel activity | |
Biological Process | proton transmembrane transport |
Keywords
- Molecular function
- Biological process
Names & Taxonomy
Protein names
- Recommended nameMatrix protein 2
- Alternative names
Gene names
Organism names
- Taxonomic lineageViruses > Riboviria > Orthornavirae > Negarnaviricota > Polyploviricotina > Insthoviricetes > Articulavirales > Orthomyxoviridae > Betainfluenzavirus > Betainfluenzavirus influenzae > Influenza B virus
- Virus hosts
Accessions
- Primary accessionP08383
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Virion membrane ; Single-pass type III membrane protein
Host cell membrane ; Single-pass type III membrane protein
Note: Transported to the plasma membrane through the trans Golgi network.
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Topological domain | 1-4 | Virion surface | |||
Transmembrane | 5-27 | Helical; Signal-anchor for type III membrane protein | |||
Topological domain | 28-109 | Intravirion | |||
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000078900 | 1-109 | Matrix protein 2 | ||
Post-translational modification
Phosphorylated by host.
Keywords
- PTM
Interaction
Subunit
Homotetramer.
Sequence
- Sequence statusComplete
- Length109
- Mass (Da)12,625
- Last updated2006-01-10 v2
- Checksum8B230F38F37F8978
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
M14909 EMBL· GenBank· DDBJ | AAA67101.1 EMBL· GenBank· DDBJ | Genomic RNA |