TABLE 1.

Rank order of Josephin domain activities versus various ubiquitin substrates

The activity of the small UCH domain enzyme Yuh1 is included for comparative purposes (35).

Substrate	Rank order
Ub-AMC	Yuh1 ≫ ATXN3L > Josephin-2 ≫ ataxin-3 ≈ ataxin-3 (full-length) ≈ Josephin-1
Ub-His6	Yuh1 ≫ Josephin-2 > ATXN3L ≫ ataxin-3 ≈ ataxin-3 (full-length) > Josephin-1
Lys-48-linked poly-Ub	ATXN3L > ataxin-3 ≫ Josephin-2 > Josephin-1 > Yuh1
Lys-63-linked poly-Ub	Josephin-2 > ATXN3L ≫ ataxin-3 > Josephin-1 > Yuh1