Complex sentence: Unlike mammalian mRNA picornaviruses do not have a 5'cap but a virally encoded protein known as VPg, however like mammalian mRNA the genome does have a poly (A) tail at the 3' end.
Split into simpler sentences: Unlike mammalian mRNA picornaviruses do not have a 5'cap but a virally encoded protein known as VPg. However, like mammalian mRNA, the genome does have a poly (A) tail at the 3' end.