Ubiquitin-conjugating enzyme E2 A (UBE2A)

Accepts ubiquitin from the E1 complicated and catalyzes its covalent attachment to other proteins. In association with the E3 enzyme BRE1 (RNF20 or RNF40), it plays a role in transcription regulation by catalyzing the monoubiquitination of histone H2B at'Lys-120' to form H2BK120ub1.

H2BK120ub1 gives a specific tag for epigenetic transcriptional activation, elongation by RNA polymerase II, telomeric silencing, and is also a prerequisite for H3K4me and H3K79me formation. In vitro catalyzes 'Lys-11', as well as 'Lys-48'-linked polyubiquitination.