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2juj
From Proteopedia
| 2juj, 15 NMR models () | |||||||||
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| Gene: | CBL, CBL2, RNF55 (Homo sapiens) | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Solution Structure of the UBA domain from c-Cbl
The Cbl proteins, RING-type E3 ubiquitin ligases, are responsible for ubiquitinating the activated tyrosine kinases and targeting them for degradation. Both c-Cbl and Cbl-b have a UBA (ubiquitin-associated) domain at their C-terminal ends, and these two UBA domains share a high sequence similarity (75%). However, only the UBA from Cbl-b, but not from c-Cbl, can bind ubiquitin (Ub). To understand the mechanism by which the UBA domains specifically interact with Ub with different affinities, we determined the solution NMR structures of these two UBA domains, cUBA from human c-Cbl and UBAb from Cbl-b. Their structures show that these two UBA domains share the same fold, a compact three-helix bundle, highly resembling the typical UBA fold. Chemical shift perturbation experiments reveal that the helix-1 and loop-1 of UBAb form a predominately hydrophobic surface for Ub binding. By comparing the Ub-interacting surface on UBAb and its counterpart on cUBA, we find that the hydrophobic patch on cUBA is interrupted by a negatively charged residue Glu12. Fluorescence titration data show that the Ala12Glu mutant of UBAb completely loses the ability to bind Ub, whereas the mutation disrupting the dimerization has no significant effect on Ub binding. This study provides structural and biochemical insights into the Ub binding specificities of the Cbl UBAs, in which the hydrophobic surface distributions on the first helix play crucial roles in their differential affinities for Ub binding. That is, the amino-acid residue diversity in the helix-1 region, but not the dimerization, determines the abilities of various UBAs binding with Ub.
Differential Ubiquitin Binding of the UBA Domains from Human c-Cbl and Cbl-b: NMR Structural and Biochemical Insights., Zhou ZR, Gao HC, Zhou CJ, Chang YG, Hong J, Song AX, Lin DH, Hu HY, Protein Sci. 2008 Jul 2;. PMID:18596201
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
2JUJ is a 1 chain structure of sequence from Homo sapiens. Full experimental information is available from OCA.
Reference
- Zhou ZR, Gao HC, Zhou CJ, Chang YG, Hong J, Song AX, Lin DH, Hu HY. Differential ubiquitin binding of the UBA domains from human c-Cbl and Cbl-b: NMR structural and biochemical insights. Protein Sci. 2008 Oct;17(10):1805-14. Epub 2008 Jul 2. PMID:18596201 doi:10.1110/ps.036384.108
Page seeded by OCA on Tue Feb 17 15:36:10 2009
Categories: Homo sapiens | Hong, J. | Hu, H Y. | Lin, D H. | Zhou, Z R. | Alpha helix | Calcium | Cytoplasm | Ligase | Metal-binding | Phosphorylation | Proto-oncogene | Sh2 domain | Uba domain | Ubl conjugation pathway | Zinc | Zinc-finger
