Abstract
Ubiquitin conjugation plays critical roles in virtually all DNA repair pathways. This review provides an overview of the known multi-domain RING/Ubox E3 ligases and their domain structures. An analysis of known RING/Ubox X-ray and NMR structures leads to a discussion of the effects of dimerization. Structural and mechanistic data relating to the E3 ligase preferences for E2 interaction and chain-type specificity are reviewed and the role of the E3 ligases in regulation of the repair pathways is discussed.