Desc: |
Catalysis of the reaction: Catalysis of the reaction: ATP + ubiquitin + protein N-ubiquityl(n)lysine = AMP + diphosphate + protein N-ubiquityl(n+1)lysine, i.e. the ligation of ubiquitin moieties, via isopeptide bonds, to extend the length of the multiubiquitin chain attached to a substrate protein. |