Active, Human, Recombinant UBE2V1/UBE2N

Background: UBE2N is a 152 amino acid UBC fold with catalytic residue Cys87; UBE2V1 is 154 amino acids, conserving the β-sheet/α-helical scaffold but replacing the active cysteine with Ser32. Crystal and NMR structures of UBE2N-ubiquitin bound to UBE2V1 (and yeast Mms2) reveal how UBE2V1 positions an acceptor ubiquitin so that its Lys63 lines up with UBE2N’s thioesterified ubiquitin. This E2 heterodimer works with diverse RING E3 enzymes. In innate-immunity, UBE2V1/UBE2N partners with TRAF6 to assemble K63 chains that recruit TAB2/TAK1 and activate NF-κB signaling. In genome maintenance, it collaborates with RAD5-like E3s to poly-ubiquitylate PCNA, licensing error-free template switching and fork reversal after DNA damage.