The function of Ensembl gene identifier ENSG00000151148 (UBE3B, ubiquitin protein ligase E3B) is as follows. 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. Ubiquitinates BCKDK and targets it for degradation, thereby regulating various metabolic processes (By similarity). Involved in the positive regulation of neurite branching in hippocampal neurons and the control of neuronal spine number and morphology, through the ubiquitination of PPP3CC (By similarity). .