Patent ID: 8273540

Claim:
A composition, comprising: a fusion protein comprising an ubiquitin ligase RING motif CXXC(X) n1 CX(H/C)(X) n2 (H/C)XXC(X) n3 CXXC, where C is a cysteine, H is a histidine, n1 is in the range of 11-14, inclusive, n2 is in the range of 2-7, inclusive and n3 is in the range of 10-20, inclusive, and X is any amino acid, wherein the ubiquitin ligase RING motif has at least 90% identity to an ubiquitin ligase RING motif selected from the group consisting of: SEQ ID NO: 8, SEQ ID NO: 14, SEQ ID NO: 20, SEQ ID NO: 26, SEQ ID NO: 32, SEQ ID NO: 38, SEQ ID NO: 44, SEQ ID NO: 50, SEQ ID NO: 56 and SEQ ID NO: 62; fused to an ubiquitin conjugating enzyme which has at least 90% identity to an ubiquitin conjugating enzyme selected from the group consisting of: SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 and SEQ ID NO: 69, the fusion protein active to transfer ubiquitin to a ubiquitylation substrate in a ubiquitinylation reaction.