E3 ubiquitin-protein ligase BRE1A is an enzyme that in humans is encoded by the RNF20 gene.[5][6][7][8][9]
The protein encoded by this gene shares similarity with BRE1 of S. cerevisiae. Yeast BRE1 is a ubiquitin ligase required for the ubiquitination of histone H2B and the methylation of histone H3.[9]