PDBsum entry 2iep

Signaling protein,transferase

PDB id: 2iep

Contents

Protein chains

187 a.a. *

Ligands

SO4 ×3

Waters ×175

* Residue conservation analysis

PDB id:

2iep

Name:

Signaling protein,transferase

Title:

Crystal structure of immunoglobulin-like domains 1 and 2 of the receptor tyrosine kinase musk

Structure:

Muscle-specific kinase receptor. Chain: a, b. Fragment: ectodomain ig1-2 (residues 22-212). Synonym: muscle, skeletal receptor tyrosine protein kinase. Musk. Engineered: yes

Source:

Rattus norvegicus. Norway rat. Organism_taxid: 10116. Gene: musk. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108.

Biol. unit:

Tetramer (from PQS)

Resolution:

2.21Å R-factor: 0.218 R-free: 0.258

Authors:

A.L.Stiegler,S.J.Burden,S.R.Hubbard

Key ref:

A.L.Stiegler et al. (2006). Crystal structure of the agrin-responsive immunoglobulin-like domains 1 and 2 of the receptor tyrosine kinase MuSK. J Mol Biol, 364, 424-433. PubMed id: 17011580 DOI: 10.1016/j.jmb.2006.09.019

Date:

19-Sep-06 Release date: 28-Nov-06

Protein chains

Q62838  (MUSK_RAT) -  Muscle, skeletal receptor tyrosine protein kinase from Rattus norvegicus

Seq: 868 a.a.

Struc: 187 a.a.

Enzyme reactions

• Enzyme class: E.C.2.7.10.1 - receptor 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: 10.1016/j.jmb.2006.09.019

J Mol Biol 364:424-433 (2006)

PubMed id: 17011580

Crystal structure of the agrin-responsive immunoglobulin-like domains 1 and 2 of the receptor tyrosine kinase MuSK.

A.L.Stiegler, S.J.Burden, S.R.Hubbard.

ABSTRACT

Muscle-specific kinase (MuSK) is a receptor tyrosine kinase expressed exclusively in skeletal muscle, where it is required for formation of the neuromuscular junction. MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. Here, we report the crystal structure of the agrin-responsive first and second immunoglobulin-like domains (Ig1 and Ig2) of the MuSK ectodomain at 2.2 A resolution. The structure reveals that MuSK Ig1 and Ig2 are Ig-like domains of the I-set subfamily, which are configured in a linear, semi-rigid arrangement. In addition to the canonical internal disulfide bridge, Ig1 contains a second, solvent-exposed disulfide bridge, which our biochemical data indicate is critical for proper folding of Ig1 and processing of MuSK. Two Ig1-2 molecules form a non-crystallographic dimer that is mediated by a unique hydrophobic patch on the surface of Ig1. Biochemical analyses of MuSK mutants introduced into MuSK(-/-) myotubes demonstrate that residues in this hydrophobic patch are critical for agrin-induced MuSK activation.

Selected figure(s)

Figure 2.
Figure 2. MuSK Ig1-2 dimer. (a) Ribbon diagram of the MuSK Ig1-2 non-crystallographic dimer. The two protomers are colored green and purple (Ig1 in light shades and Ig2 in dark shades). The non-crystallographic 2-fold axis is vertical. (b) Ig1–Ig1 dimer interface. The stereo view is approximately 50° about the vertical (2-fold) axis from that in (a). Side-chain atoms in the dimer interface are shown in ball-and-stick representation, and hydrophobic contacts are shown with semi-transparent van der Waals surfaces. Carbon atoms, either green or purple; oxygen atoms, red; and sulfur atoms, yellow. Side-chains that are not labeled are related by the vertical 2-fold axis to those that are labeled. (c) Molecular surface representation of Ig1-2 colored according to electrostatic potential: blue, positive (+ 15kT); white, neutral; red, negative (− 15kT). Residues located in the Ig1 dimer interface (left) and in the vicinity of the surface-exposed disulfide bridge (Cys98/Cys112) (right), on the opposite side of Ig1, are labeled. The two views are related by 180° about a vertical axis. (a) and (b) were rendered with PyMOL [http://pymol.sourceforge.net] and (c) with GRASP.^45

Figure 4.
Figure 4. Mutations in MuSK Ig1 affect agrin-induced receptor activation. (a) Ile96 and (b) Met48 and Leu83 are required for agrin-induced activation. MuSK^−/− myotubes stably expressing MuSK-GFP (wild-type or mutant) were stimulated with 0.1 nM or 0.5 nM neural agrin for 30 min followed by MuSK immunoprecipitation (IP) with the C-terminal anti-MuSK antibody. IP samples were resolved by SDS-PAGE and immunoblotted (IB) with an anti-phosphotyrosine antibody (anti-pTyr) to assess MuSK activation. Blotting a duplicate membrane with anti-GFP antibody shows the relative level of MuSK-GFP in each sample.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2006, 364, 424-433) copyright 2006.

Figures were selected by an automated process.