PDBsum entry 1qu0

Metal binding protein

PDB id: 1qu0

Contents

Protein chains

181 a.a. *

Ligands

SO4 ×7

Metals

_CA ×4

Waters ×275

* Residue conservation analysis

PDB id:

1qu0

Name:

Metal binding protein

Title:

Crystal structure of the fifth laminin g-like module of the mouse laminin alpha2 chain

Structure:

Laminin alpha2 chain. Chain: a, b, c, d. Fragment: lg5 module. Engineered: yes. Mutation: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090.

Biol. unit:

Dimer (from PQS)

Resolution:

2.35Å R-factor: 0.229 R-free: 0.255

Authors:

E.Hohenester,D.Tisi,J.F.Talts,R.Timpl

Key ref:

E.Hohenester et al. (1999). The crystal structure of a laminin G-like module reveals the molecular basis of alpha-dystroglycan binding to laminins, perlecan, and agrin. Mol Cell, 4, 783-792. PubMed id: 10619025 DOI: 10.1016/S1097-2765(00)80388-3

Date:

05-Jul-99 Release date: 03-Dec-99

Protein chains

Q60675  (LAMA2_MOUSE) -  Laminin subunit alpha-2 from Mus musculus

Seq: 3118 a.a.

Struc: 181 a.a.*

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

DOI no: 10.1016/S1097-2765(00)80388-3

Mol Cell 4:783-792 (1999)

PubMed id: 10619025

The crystal structure of a laminin G-like module reveals the molecular basis of alpha-dystroglycan binding to laminins, perlecan, and agrin.

E.Hohenester, D.Tisi, J.F.Talts, R.Timpl.

ABSTRACT

Laminin G-like (LG) modules in the extracellular matrix glycoproteins laminin, perlecan, and agrin mediate the binding to heparin and the cell surface receptor alpha-dystroglycan (alpha-DG). These interactions are crucial to basement membrane assembly, as well as muscle and nerve cell function. The crystal structure of the laminin alpha 2 chain LG5 module reveals a 14-stranded beta sandwich. A calcium ion is bound to one edge of the sandwich by conserved acidic residues and is surrounded by residues implicated in heparin and alpha-DG binding. A calcium-coordinated sulfate ion is suggested to mimic the binding of anionic oligosaccharides. The structure demonstrates a conserved function of the LG module in calcium-dependent lectin-like alpha-DG binding.

Selected figure(s)

Figure 3.
Figure 3. The Calcium Binding SiteStereo view of the calcium binding site in α2LG5 in a similar view as Figure 2. The calcium ion is shown as a pink sphere. Residues coordinating to the calcium ion are labeled. Hydrogen bonds to the sulfate ion (see text) are shown as grey lines. A water molecule is also bound to the calcium ion but is not shown for clarity. The electron density shown is a difference Fourier map of the Sm derivative calculated with the final model phases and contoured at 10σ.

Figure 4.
Figure 4. Comparison of the LG Module and Pentraxin Folds(A) α2LG5 and (B) human SAP ([17]). Disulfide bridges are in yellow, and calcium ions are shown as pink spheres. The SAP subunit is viewed approximately down the 5-fold axis of the SAP pentamer. Regions involved in subunit contacts in the pentamer are indicated by the black arrows.

The above figures are reprinted by permission from Cell Press: Mol Cell (1999, 4, 783-792) copyright 1999.

Figures were selected by an automated process.