Table 2.

S-P-A motif conservation in E2 enzymes

E2 enzyme	Loop 7 Sequence	Interacts w. CHIP?	Reference
Ubc1	DQWAAA	N	[20]
UbcH2	QTWTAL	N	[20]
Ubc3	ERWNPT	N	[18, 20]
UbcH7	ENWKPA	N	[18, 20]
UbcH8	ENWKPC	N	[18]
UbcH5a-c	SQWSPA	Y	[20]
Ubc13	DKWSPA	Y	[22, 24]
Ube2e1-3	DNWSPA	Y	*

Residues on loop 7 of selected E2 enzymes, corresponding to the positions of the S-P-A motifs in UbcH5 and Ubc13.

*Reported in this study.