The substrate binding site is located in the cleft between N and C-terminal domains, but most of the catalytic residues are found in the larger C-terminal domain.
The SOCS box acts as a bridge between specific substrate- binding domains and more generic proteins that comprise a large family of E3 ubiquitin protein ligases.
This family contains a number of ubiquitin-like proteins: SUMO (smt3 homologue) (see Swiss:Q02724), Nedd8 (see Swiss:P29595), Elongin B (see Swiss:Q15370), Rub1 (see Swiss:Q9SHE7), and Parkin (see Swiss:O60260). A number of them are thought to carry ...
This family contains a number of ubiquitin-like proteins: SUMO (smt3 homologue) (see Swiss:Q02724), Nedd8 (see Swiss:P29595), Elongin B (see Swiss:Q15370), Rub1 (see Swiss:Q9SHE7), and Parkin (see Swiss:O60260). A number of them are thought to carry a distinctive five-residue motif termed the proteasome-interacting motif (PIM), which may have a biologically significant role in protein delivery to proteasomes and recruitment of proteasomes to transcription sites [5].