2MQ1

Phosphotyrosine binding domain

Summary for 2MQ1

• Entry DOI: 10.2210/pdb2mq1/pdb
• NMR Information: BMRB: 25008
• Descriptor: E3 ubiquitin-protein ligase Hakai, ZINC ION (2 entities in total)
• Functional Keywords: phosphotyrosine binding, ligase
• Biological source: Mus musculus (mouse)
• Total number of polymer chains: 1
• Total formula weight: 10415.37

Authors

Mukherjee, M.,Jing-Song, F.,Sivaraman, J. (deposition date: 2014-06-11, release date: 2014-08-06, Last modification date: 2024-05-15)

Primary citation

Mukherjee, M.,Jing-Song, F.,Ramachandran, S.,Guy, G.R.,Sivaraman, J.
Dimeric switch of Hakai-truncated monomers during substrate recognition: insights from solution studies and NMR structure.
J.Biol.Chem., 289:25611-25623, 2014

PubMed Abstract: Hakai, an E3 ubiquitin ligase, disrupts cell-cell contacts in epithelial cells and is up-regulated in human colon and gastric adenocarcinomas. Hakai acts through its phosphotyrosine-binding (HYB) domain, which bears a dimeric fold that recognizes the phosphotyrosine motifs of E-cadherin, cortactin, DOK1, and other Src substrates. Unlike the monomeric nature of the SH2 and phosphotyrosine-binding domains, the architecture of the HYB domain consists of an atypical, zinc-coordinated tight homodimer. Here, we report a C-terminal truncation mutant of the HYB domain (HYB(ΔC)), comprising amino acids 106-194, which exists as a monomer in solution. The NMR structure revealed that this deletion mutant undergoes a dramatic structural change caused by a rearrangement of the atypical zinc-coordinated unit in the C terminus of the HYB domain to a C2H2-like zinc finger in HYB(ΔC). Moreover, using isothermal titration calorimetry, we show that dimerization of HYB(ΔC) can be induced using a phosphotyrosine substrate peptide. This ligand-induced dimerization of HYB(ΔC) is further validated using analytical ultracentrifugation, size-exclusion chromatography, NMR relaxation studies, dynamic light scattering, and circular dichroism experiments. Overall, these observations suggest that the dimeric architecture of the HYB domain is essential for the phosphotyrosine-binding property of Hakai.

PubMed: 25074933
DOI: 10.1074/jbc.M114.592840

Experimental method

SOLUTION NMR