Structural basis of ubiquitin recognition by the ubiquitin-associated (UBA) domain of the ubiquitin ligase EDD.
EDD (or HYD) is an E3 ubiquitin ligase in the family of HECT (homologous to E6-AP C terminus) ligases. EDD contains an N-terminal ubiquitin-associated (UBA) domain, which is present in a variety of proteins involved in ubiquitin-mediated processes. Here, we use isothermal titration calorimetry (ITC), NMR titrations, and pull-down assays to show that the EDD UBA domain binds ubiquitin. The 1.85 A crystal structure of the complex with ubiquitin reveals the structural basis of ubiquitin recognition by UBA helices alpha1 and alpha3. The structure shows a larger number of intermolecular hydrogen bonds than observed in previous UBA/ubiquitin complexes. Two of these involve ordered water molecules. The functional importance of residues at the UBA/ubiquitin interface was confirmed using site-directed mutagenesis. Surface plasmon resonance (SPR) measurements show that the EDD UBA domain does not have a strong preference for polyubiquitin chains over monoubiquitin. This suggests that EDD binds to monoubiquitinated proteins, which is consistent with its involvement in DNA damage repair pathways.
Kozlov
Guennadi
G
Department of Biochemistry, McGill University, Montréal, Québec H3G 1Y6, Canada.
Nguyen
Long
L
Lin
Tong
T
De Crescenzo
Gregory
G
Park
Morag
M
Gehring
Kalle
K
D002151:Calorimetry; D018360:Crystallography, X-Ray; D004249:DNA Damage / Q000502:physiology; D004260:DNA Repair / Q000502:physiology; D006801:Humans; D011485:Protein Binding / Q000502:physiology; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary / Q000502:physiology; D020349:Surface Plasmon Resonance; D025801:Ubiquitin / Q000737:chemistry* / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry* / Q000378:metabolism
D025801:Ubiquitin; C117617:UBR5 protein, human; D044767:Ubiquitin-Protein Ligases