E3 ubiquitin-protein ligase which accepts ubiquitin from E2 ubiquitin-conjugating enzymes ube2l3 and ube2l6 in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. [E2 ubiquitin-conjugating enzyme]-S-ubiquitinyl-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-N(6)-ubiquitinyl-L-lysine. Protein modification; protein ubiquitination. Members of the RBR family are atypical E3 ligases. They interact with the E2 conjugating enzyme UBE2L3 and function like HECT-type E3 enzymes: they bind E2s via the first RING domain, but require an obligate trans-thiolation step during the ubiquitin transfer, requiring a conserved cysteine residue in the second RING domain. Belongs to the RBR family. RNF144 subfamily. Lacks the His residue in the RING-type domain 2 that is one of the conserved features of the family.