PDBsum entry 4xz1

Transferase/transferase inhibitor

PDB id: 4xz1

Contents

Protein chains

254 a.a.

17 a.a.

Ligands

4N6

PDB id:

4xz1

Name:

Transferase/transferase inhibitor

Title:

Zap-70-tsh2:compound-b adduct

Structure:

Tyrosine-protein kinase zap-70. Chain: a. Synonym: 70 kda zeta-chain associated protein,syk-related tyrosine kinase. Engineered: yes. Doubly phosphorylated itam peptide. Chain: b. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: zap70, srk. Expressed in: escherichia coli. Expression_system_taxid: 562. Synthetic: yes. Organism_taxid: 9606

Resolution:

2.80Å R-factor: 0.218 R-free: 0.270

Authors:

T.Barros,J.Kuriyan,J.A.Winger,P.R.Visperas

Key ref:

P.R.Visperas et al. (2015). Modification by covalent reaction or oxidation of cysteine residues in the tandem-SH2 domains of ZAP-70 and Syk can block phosphopeptide binding. Biochem J, 465, 149-161. PubMed id: 25287889 DOI: 10.1042/BJ20140793

Date:

03-Feb-15 Release date: 29-Jul-15

Protein chain

P43403  (ZAP70_HUMAN) -  Tyrosine-protein kinase ZAP-70 from Homo sapiens

Seq: 619 a.a.

Struc: 254 a.a.*

Protein chain

P20963  (CD3Z_HUMAN) -  T-cell surface glycoprotein CD3 zeta chain from Homo sapiens

Seq: 164 a.a.

Struc: 17 a.a.

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: Chain A: E.C.2.7.10.2 - non-specific protein-tyrosine kinase.
• Reaction: L-tyrosyl-[protein] + ATP = O-phospho-L-tyrosyl-[protein] + ADP + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1042/BJ20140793

Biochem J 465:149-161 (2015)

PubMed id: 25287889

Modification by covalent reaction or oxidation of cysteine residues in the tandem-SH2 domains of ZAP-70 and Syk can block phosphopeptide binding.

P.R.Visperas, J.A.Winger, T.M.Horton, N.H.Shah, D.J.Aum, A.Tao, T.Barros, Q.Yan, C.G.Wilson, M.R.Arkin, A.Weiss, J.Kuriyan.

ABSTRACT

Zeta-chain associated protein of 70 kDa (ZAP-70) and spleen tyrosine kinase (Syk) are non-receptor tyrosine kinases that are essential for T-cell and B-cell antigen receptor signalling respectively. They are recruited, via their tandem-SH2 (Src-homology domain 2) domains, to doubly phosphorylated immunoreceptor tyrosine-based activation motifs (ITAMs) on invariant chains of immune antigen receptors. Because of their critical roles in immune signalling, ZAP-70 and Syk are targets for the development of drugs for autoimmune diseases. We show that three thiol-reactive small molecules can prevent the tandem-SH2 domains of ZAP-70 and Syk from binding to phosphorylated ITAMs. We identify a specific cysteine residue in the phosphotyrosine-binding pocket of each protein (Cys39 in ZAP-70, Cys206 in Syk) that is necessary for inhibition by two of these compounds. We also find that ITAM binding to ZAP-70 and Syk is sensitive to the presence of H2O2 and these two cysteine residues are also necessary for inhibition by H2O2. Our findings suggest a mechanism by which the reactive oxygen species generated during responses to antigen could attenuate signalling through these kinases and may also inform the development of ZAP-70 and Syk inhibitors that bind covalently to their SH2 domains.