Ubiquitin-like modifier-activating enzyme 7 is a protein in humans that is encoded by UBA7 gene. Activates ubiquitin by first adenylating with ATP its C-terminal glycine residue and thereafter linking this residue to the side chain of a cysteine residue in E1, yielding a ubiquitin-E1 thioester and free AMP. Catalyzes the ISGylation of influenza A virus NS1 protein.