Homologous Superfamily

Mu1 membrane penetration protein, subdomain 2 (IPR015962)

Short name: Mu1_membr_pen_sub2

Overlapping entries


Mu1 is an outer capsid protein that acts as a reoviral penetration agent. Non-enveloped animal reoviruses must enter host cells by membrane penetration that does not involve membrane fusion, as they lack a viral membrane. Reoviruses are activated by proteolytic cleavage in the intestinal lumen, leading to infectious subviral particles. The core of the virus is coated by a layer of mu1 and sigma3 proteins. Proteases strip off sigma3 exposing mu1, which provides the membrane penetration machinery that perforates the membrane. In addition, N-terminal myristoylation of polypeptide Mu1 are required for site-specific cleavage to Mu1C in transfected cells [PMID: 1548757]. Mu1 forms a trimer, where the three mu1 molecules are coiled around one another with a right-handed twist. The mu1 chain folds into four distinct domains: three intertwined, predominantly alpha helical domains and a jelly-roll beta-sandwich [PMID: 11832217].

This superfamily represents one of the two alpha-bundle domains. Another outer capsid protein, VP4, also contains the alpha-bundle like domain.

GO terms

Biological Process

GO:0009405 pathogenesis
GO:0046718 viral entry into host cell

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.