E3 ubiquitin-protein ligase which accepts ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates.
(Microbial infection) Catalyzes ubiquitination of Botulinum neurotoxin A light chain (LC) of C.botulinum neurotoxin type A (BoNT/A).