(a) Cartoon of experimental scheme, monitoring reactivity
of UBE2D3~UB (D refers to the “donor” UB to be transferred from
E2) in the presence of the E3 RING domain from RNF4 and formation of di-UB with
UBC4 acceptor (UBA). The distribution of diUB linkage
types generated is shown. (b) same as (a), except with fluorescent
donor UB and various acceptor UBs (UBA). Notice that di-UB products
with distinct electrophoretic mobilities were observed for each acceptor,
indicating that the lysine analogs likely affect the di-UB chain linkage
identity (N=2 independent experiments). (c) Relative fold changes
of diUB linkage types for reactions with UBE2D3 and the E3 RING domain from RNF4
comparing K11UBC5, K48UBC5, or
K63UBC5 acceptors with UBC4. N.D. is
not-defined. (d) Plot showing the relative changes in UBE2D3/RNF4
generated di-UB chain linkages when comparing products containing
K48UBC5 or UBC4 acceptors. For (c) and (d)
N=3 technical replicates.