PDBsum entry 1blj

Phosphorylation

PDB id: 1blj

Contents

Protein chain

114 a.a. *

* Residue conservation analysis

PDB id:

1blj

Name:

Phosphorylation

Title:

Nmr ensemble of blk sh2 domain, 20 structures

Structure:

P55 blk protein tyrosine kinase. Chain: a. Fragment: sh2 domain, src homology 2. Engineered: yes. Other_details: peptide free

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Gene: p55 blk kinase (residues 107 -. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

NMR struc:

20 models

Authors:

W.J.Metzler,B.Leiting,K.Pryor,L.Mueller,B.T.Farmer Ii

Key ref:

W.J.Metzler et al. (1996). The three-dimensional solution structure of the SH2 domain from p55blk kinase. Biochemistry, 35, 6201-6211. PubMed id: 8639560 DOI: 10.1021/bi960157x

Date:

26-Mar-96 Release date: 12-Mar-97

Protein chain

P16277  (BLK_MOUSE) -  Tyrosine-protein kinase Blk from Mus musculus

Seq: 499 a.a.

Struc: 114 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: 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: 10.1021/bi960157x

Biochemistry 35:6201-6211 (1996)

PubMed id: 8639560

The three-dimensional solution structure of the SH2 domain from p55blk kinase.

W.J.Metzler, B.Leiting, K.Pryor, L.Mueller, B.T.Farmer.

ABSTRACT

Signal transduction in B cells is mediated, in part, by the interaction of the cytoplasmic components of the antigen receptor complex and various members of the src family tyrosine kinases. Key to this process appears to be the interaction of the tyrosine kinase SH2 domains with the tyrosine-phosphorylated cytoplasmic domain of Ig-alpha, a disulfide-bonded heterodimeric (with Ig-beta or Ig-gamma) transmembrane protein that noncovalently associates with the antigen receptor immunoglobin chains. In addition to binding to the phosphorylated cytoplasmic domains of Ig-alpha and Ig-beta, blk and fyn(T), two members of the src family kinases, have been shown to bind overlapping but distinct sets of phosphoproteins [Malek & Desiderio (1993) J. Biol. Chem. 268. 22557-22565]. A comparison of their three-dimensional structures may elucidate the apparently subtle differences required for phosphoprotein discrimination. To begin characterizing the blk/fyn/phosphosphoprotein interactions, we have determined the three-dimensional solution structure of the SH2 domain of blk kinase by nuclear magnetic resonance (NMR) spectroscopy. 1H, 13C, and 15N resonances of the SH2 domain of blk kinase were assigned by analysis of multidimensional, double- and triple-resonance NMR experiments. Twenty structures of the blk SH2 domain were refined with the program X-PLOR using a total of 2080 experimentally derived conformational restraints. The structures converged to a root-mean-squared (rms) distance deviation of 0.51 and 0.95 A for the backbone atoms and for the non-hydrogen atoms, respectively. The blk SH2 domain adopts the prototypical SH2 fold. Structurally, blk SH2 is most similar to the crystal structure of the v-src SH2 domain [Waksman et al. (1993) Nature 358.646-653] and superimposes on the crystal structure with an rmsd of 1.52 A for the backbone atoms. The largest deviations occur in the four loops interconnecting beta-strands A-E, which are the least well-defined regions in the NMR structure. Exclusion of these loops lowers this rmsd to 0.82 A. The conformation of the BC loop in the blk SH2 domain is similar to the open conformation in the apo lck SH2 domain, suggesting that, like the lck SH2 domain, the blk SH2 domain may have a gated phosphopeptide binding site. Finally, it is proposed that the amino acid substitution of Lys 88 (blk) for Glu [fyn(T)] is important for the observed differences in specificity between blk and fyn(T) SH2 domains.