Influenza virus protein domain, molecular model. This is an effector domain, a non-structural protein fragment that facilitates interactions. This domain is from a mutant influenza A (subtype H5N1) that was identified in Vietnam in 2004. The mutation is named W182A. Influenza A virus subtype H5N1 is an avian influenza found in birds in South-East Asia. It can be contracted by humans and can be fatal.