Journal Article

Structure of a novel phosphotyrosine-binding domain in Hakai that targets E-cadherin

Yew, Jingxi, Li, Dan, Zhou, Xingding, Ng, Cherlyn, Asgar, Nur Farehan M, Yim, Daniel, Seetharaman, J, Sze, Siu Kwan, Koh, Xiao Woon, Sinniah, Saravanan, Yusoff, Permeen, Jackson, Rebecca A, Qian, Jingru, Mukherjee, Manjeet, Chow, Soah Yee, Iyu, Audrey, Sivaraman, J, Guy, Graeme R, Lim, Yoon Pin

2012

Overview

Phosphotyrosine‐binding domains, typified by the SH2 ( S rc h omology 2) and PTB domains, are critical upstream components of signal transduction pathways. The E3 ubiquitin ligase Hakai targets tyrosine‐phosphorylated E‐cadherin via an uncharacterized domain. In this study, the crystal structure of Hakai (amino acids 106–206) revealed that it forms an atypical, zinc‐coordinated homodimer by utilizing residues from the phosphotyrosine‐binding domain of two Hakai monomers. Hakai dimerization allows the formation of a phosphotyrosine‐binding pocket that recognizes specific phosphorylated tyrosines and flanking acidic amino acids of Src substrates, such as E‐cadherin, cortactin and DOK1. NMR and mutational analysis identified the Hakai residues required for target binding within the binding pocket, now named the HYB domain. ZNF645 also possesses a HYB domain but demonstrates different target specificities. The HYB domain is structurally different from other phosphotyrosine‐binding domains and is a potential drug target due to its novel structural features. In this article, the authors characterize the phosphotyrosine‐binding domain of the E3 ubiquitin ligase Hakai. They find that Hakai homodimerizes to form a phosphotyrosine‐binding pocket that recognizes Src targets. This represents a novel phosphotyrosine recognition structure, fundamentally different from the previously known SH2 and PTB domains.

• Publisher: John Wiley & Sons, Ltd,Nature Publishing Group UK,Springer Nature B.V,Nature Publishing Group
• Subject: Amino Acid Sequence / Amino acids / Cadherins - metabolism / Crystal structure / Crystallography, X-Ray / DNA Mutational Analysis / EMBO05 / EMBO37 / Enzymes / Eukaryotes / Hakai / Magnetic Resonance Spectroscopy / Models, Molecular / Molecular biology / Molecular Sequence Data / phosphotyrosine / Protein Binding / Protein Multimerization / Protein Structure, Quaternary / Protein Structure, Tertiary / Residues / Signal transduction / Src substrates / Substrates / ubiquitin ligases / Ubiquitin-Protein Ligases - chemistry / Ubiquitin-Protein Ligases - metabolism / Upstream / zinc fingers