Structure of the human FANCL RING-Ube2T complex reveals determinants of cognate E3-E2 selection.

The combination of an E2 ubiquitin-conjugating enzyme with an E3 ubiquitin-ligase is essential for ubiquitin modification of a substrate. Moreover, the pairing dictates both the substrate choice and the modification type. The molecular details of generic E3-E2 interactions are well established.