EC Number   |
Substrates |
Organism |
Products |
Reversibility |
|---|
   2.3.2.26 | more |
HECT ligases directly catalyse protein ubiquitination and non-covalently interact with ubiquitin. The ubiquitin bindung surface on the HECT might act to bind a ubiquitin moiety that is already conjugated to a protein substrate, thus promoting polyubiquitination. Mutation in the ubiquitin bindung surface (F707A and Y605A) mutants strongly impairs free-chain formation and ubiquitination of all substrates tested |
Homo sapiens |
? |
- |
? |
| 2.3.2.26 | more |
Nedd4 has a strong preference for building Lys63 ubiquitin-chains on substrates. Mutant F707A has defective chain elongation on substrate or shorter free chains |
Homo sapiens |
? |
- |
? |
| 2.3.2.26 | more |
C2 domain of isoform Smurf1 functions in substrate selection |
Homo sapiens |
? |
- |
? |
| 2.3.2.26 | more |
high-risk human papilloma virus E6 oncoproteins interact with the ubiquitin ligase E6AP and target several cellular proteins, including p53 and proteins of the MAGI family, towards ubiquitin-mediated degradation. E6 oncoproteins from major high-risk human papilloma virus types 16, 18, 33 and 58 bind to a 15-mer peptide containing the LxxphiLsh motif of E6AP, where L indicates conserved leucine residues, phi is a hydrophobic residue, h is an amino acid residue with a side-chain capable of accepting hydrogen bonds, s represents a small amino acid residue and xx is a dipeptide where one of the residues is Asp, Asn, Glu or Gln. The equilibrium dissociation constants are in the low micromolar range. Low-risk human papilloma virus 11 E6 does not interact with E6AP. The two zinc-binding domains of E6 are required for E6AP recognition |
Homo sapiens |
? |
- |
? |
| 2.3.2.26 | more |
isoform E6-AP is loaded with ubiquitin by E2 enzyme UbcH5. A region of UbcH5 encompassing the catalytic site cysteine residue is critical for its ability to interact with E6-AP |
Homo sapiens |
? |
- |
? |
| 2.3.2.26 | more |
isoform Rsp5 is loaded with ubiquitin by E2 enzyme UbcH5. A region of UbcH5 encompassing the catalytic site cysteine residue is critical for its ability to interact with RSP5 |
Saccharomyces cerevisiae |
? |
- |
? |
| 2.3.2.26 | more |
isoform UPL5 interacts with transcription factor WRKY53 via its leucine zipper domain |
Arabidopsis thaliana |
? |
- |
? |
| 2.3.2.26 | more |
the type-1/2 substrate-binding sites of isoform UBR1, are located in the first 700 residues of the 1950-residue enzyme. Type-1 site is specific for basic N-terminal residues Arg, Lys, and His. The type-2 site is specific for bulky hydrophobic N-terminal residues Trp, Phe, Tyr, Leu, and Ile. Isoform UBR1 binds, with a Kd of about 1microM to either type-1 or type-2 N-terminal residues of reporter peptides but does not bind to a stabilizing N-terminal residue such as Gly |
Saccharomyces cerevisiae |
? |
- |
? |
| 2.3.2.26 | more |
ubiquitin ligases HECT E3 use a two-step mechanism to ligate ubiquitin to target proteins. The second step of ligation is mediated by a distinct catalytic architecture established by both the HECT E3 and its covalently linked ubiquitin. There exist three-way interactions between ubiquitin and the bilobal HECT domain orienting the E3-ubiquitin thioester bond for ligation, and restricting the location of the substrate-binding domain to prioritize targets lysines for ubiquitination |
Saccharomyces cerevisiae |
? |
- |
? |
| 2.3.2.26 | more |
UBR1 and CUP9, a transcriptional repressor of peptide import, interact nonspecifically and specific binding which involves, in particular, the binding by cognate dipeptides to theUBR1 type-1/2 substrate-binding sites, can be restored either by a chaperone such as EF1A or through macromolecular crowding |
Saccharomyces cerevisiae |
? |
- |
? |
