| Type: | Domain | Name: | Mu1 membrane penetration protein, alpha/beta subdomain |
| Description: | 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 is required for site-specific cleavage to Mu1C in transfected cells []. 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 []. This entry represents a domain with a complex alpha-helical and beta-sheet structure. | Short Name: | Mu1_membr_pen_a/b_sub |
