2G57

Structure of the Phosphorylation Motif of the oncogenic Protein beta-Catenin Recognized By a Selective Monoclonal Antibody

Summary for 2G57

• Entry DOI: 10.2210/pdb2g57/pdb
• NMR Information: BMRB: 7001
• Descriptor: Beta-catenin (1 entity in total)
• Functional Keywords: beta-catenin oncogenic protein, p-beta-catenin phosphorylated peptide, epitope mapping, antibody, p-beta-catenin-antibody complex, std-nmr, trnoesy, restrained molecular dynamics, bound structure, binding fragment, oncoprotein
• Cellular location: Cytoplasm: P35222
• Total number of polymer chains: 1
• Total formula weight: 2928.95

Authors

Megy, S.,Bertho, G.,Gharbi-Benarous, J.,Baleux, F.,Benarous, R.,Girault, J.P. (deposition date: 2006-02-22, release date: 2006-03-28, Last modification date: 2024-11-13)

Primary citation

Megy, S.,Bertho, G.,Gharbi-Benarous, J.,Baleux, F.,Benarous, R.,Girault, J.P.
STD and TRNOESY NMR studies for the epitope mapping of the phosphorylation motif of the oncogenic protein beta-catenin recognized by a selective monoclonal antibody
Febs Lett., 580:5411-5422, 2006

PubMed Abstract: The interaction of the P-beta-Cat(19-44) peptide, a 26 amino acid peptide (K(19)AAVSHWQQQSYLDpSGIHpSGATTTAP(44)) that mimics the phosphorylated beta-Catenin antigen, has been studied with its monoclonal antibody BC-22, by transferred nuclear Overhauser effect NMR spectroscopy (TRNOESY) and saturation transfer difference NMR (STD NMR) spectroscopy. This antibody is specific to diphosphorylated beta-Catenin and does not react with the non-phosphorylated protein. Phosphorylation of beta-Catenin at sites Ser33 and Ser37 on the DSGXXS motif is required for the interaction of beta-Catenin with the ubiquitin ligase SCF(beta-TrCP). beta-TrCP is involved in the ubiquitination and proteasome targeting of the oncogenic protein beta-Catenin, the accumulation of which has been implicated in various human cancers. The three-dimensional structure of the P-beta-Cat(19-44) in the bound conformation was determined by TRNOESY NMR experiments; the peptide adopts a compact structure in the presence of mAb with formation of turns around Trp25 and Gln26, with a tight bend created by the DpS(33)GIHpS(37) motif; the peptide residues (D32-pS37) forming this bend are recognized by the antibody as demonstrated by STD NMR experiments. STD NMR studies provide evidence for the existence of a conformational epitope containing tandem repeats of phosphoserine motifs. The peptide's epitope is predominantly located in the large bend and in the N-terminal segment, implicating bidentate association. These findings are in excellent agreement with a recently published NMR structure required for the interaction of beta-Catenin with the SCF(beta-TrCP) protein.

PubMed: 16996060
DOI: 10.1016/j.febslet.2006.08.084

Experimental method

SOLUTION NMR