M1 protein
Template:Infobox protein family
The M1 protein is a matrix protein of the influenza virus. It forms a coat inside the viral envelope. This is a bifunctional membrane/RNA-binding protein that mediates the encapsidation of nucleoprotein cores into the membrane envelope. It is therefore required that M1 binds both membrane and RNA simultaneously.[1]
The M1 protein binds to the viral RNA. The binding is not specific to any RNA sequence, and is performed via a peptide sequence rich in basic amino acids.Script error: No such module "Unsubst".
It also has multiple regulatory functions, performed by interaction with the components of the host cell. The mechanisms regulated include a role in the export of the viral ribonucleoproteins from the host cell nucleus, inhibition of viral transcription, and a role in the virus assembly and budding. The protein was found to undergo phosphorylation in the host cell.Script error: No such module "Unsubst".
The M1 protein forms a layer under the patches of host cell membrane that are rich with the viral hemagglutinin, neuraminidase and M2 transmembrane proteins, and facilitates budding of the mature viruses.Script error: No such module "Unsubst".
M1 consists of two domains connected by a linker sequence. The N-terminal domain has a multi-helical structure that can be divided into two subdomains.[2] The C-terminal domain also contains alpha-helical structure.