Table 1.

Representative list of reactive cysteines within E3 ligases^*

E3 ligase	Uniprot ID	Reactive Cysteine(s)
RNF114	Q9Y4L5	C8**, C110
RNF4	P78317	C132/C135**
DCAF16	Q9NXF7	C177 or C179**
DCAF11	Q8TEB1	C460**
FEM1B	Q9UK73	C186**
CRBN	Q96SW2	C188***, C287
VHL	P40337	C77***
RNF2	C99496	C72***
RNF14	Q9UBS8	C262***, C417
RNF20	Q5VTR2	C383, C905, C924
RNF25	Q96BH1	C316***
RNF31	Q96EP0	C504***, C551
RNF111	Q6ZNA4	C968***
RNF113A	O15541	C15***
RNF123	Q5XPI4	C461***
RNF126	Q9BV68	C32
RNF128	Q8TEB7	C15***
RNF130	Q86XS8	C320***
RNF149	Q8NC42	C295***
RNF167	Q9H6Y7	C271***
RNF180	Q86T96	C28***
RNF213	Q63HN8	C614***
UBR1	Q8IWV7	C180, C1603***
UBR2	Q8IWV8	C1360, C1619***, C576
UBR4	Q5T4S7	C1358, C2554***, C4049, C2222, C1274
ZNF598	Q86UK7	C456***
KCTD21	Q4G0X4	C166***
KBTBD7	Q8WVZ9	C527/C529***
KLHL20	Q9Y2M5	C356***
KLHL24	Q6TFL4	C359***
KEAP1	Q14145	C23, C288, C196, C319
FBXL18	Q96ME1	C468***
FBXL7	Q9UJT9	C386/C401***
FBXW8	Q8N3Y1	C579***
FBXO10	Q9UK96	C430***
FBXO22	Q8NEZ5	C228***
FBXO30	Q8TB52	C592***, C433, C723/C725
FBXO9	Q9UK97	C68***
SKP1	P63208	C120, C160
SKP2	Q13309	C113***, C240, C205, C345
ASB6	Q9NWX5	C153***
ASB9	Q96DX5	C216***
RAB40C	Q96S21	C159***
NOSIP	Q9Y314	C8***
PRPF19	Q9UMS4	C298***, C230, C351
STUB1	Q9UNE7	C199***, C48
UBE4A	Q14139	C79***, C989, C1002
DCAF5	Q96JK2	C503***
DCAF7	P61962	C61***, C120
DCAF8	Q5TAQ9	C297, C272
DCAF13	Q9NV06	C190, C215, C120

^*Reactive cysteines annotated are derived from the aggregate chemoproteomic data in Table S1. Listed cysteines show at least 7 aggregate spectral counts for the particular site.

^**From experimental data from Zhang, Cravatt et al. 2019; Spradlin, Nomura et al. 2019; Ward, Nomura et al. 2019; Zhang, Cravatt et al. 2021; or Henning, Nomura et al. 2021^{65,66,81,82,100}.

^***Represents the dominant probe-modified site over other sites identified in the same E3 ligase from the aggregate chemoproteomic data in Table S1.