PDBsum entry 1qg3

Structural protein

PDB id: 1qg3

Contents

Protein chain

195 a.a. *

Ligands

CAC ×2

SO4 ×3

Waters ×381

* Residue conservation analysis

PDB id:

1qg3

Name:

Structural protein

Title:

Crystal structure of a tandem pair of fibronectin type iii domains from the cytoplasmic tail of integrin alpha6 beta4

Structure:

Protein (integrin beta-4 subunit). Chain: a, b. Fragment: first tandem pair of fibronectin type iii domains. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: itgb4. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PQS)

Resolution:

2.15Å R-factor: 0.201 R-free: 0.262

Authors:

J.M.De Pereda,G.Wiche,R.C.Liddington

Key ref:

J.M.de Pereda et al. (1999). Crystal structure of a tandem pair of fibronectin type III domains from the cytoplasmic tail of integrin alpha6beta4. EMBO J, 18, 4087-4095. PubMed id: 10428948 DOI: 10.1093/emboj/18.15.4087

Date:

19-Apr-99 Release date: 20-Aug-99

Protein chains

P16144  (ITB4_HUMAN) -  Integrin beta-4 from Homo sapiens

Seq: 1822 a.a.

Struc: 195 a.a.

DOI no: 10.1093/emboj/18.15.4087

EMBO J 18:4087-4095 (1999)

PubMed id: 10428948

Crystal structure of a tandem pair of fibronectin type III domains from the cytoplasmic tail of integrin alpha6beta4.

J.M.de Pereda, G.Wiche, R.C.Liddington.

ABSTRACT

The integrin alpha6beta4 is an essential component of hemidesmosomes but it also plays a dynamic role in invasive carcinoma cells. The cytoplasmic tail of the beta4 subunit is uniquely large among integrins and includes two pairs of fibronectin type III domains separated by a connecting segment. Here we describe the crystal structure of the first tandem domain pair, a module that is critical for alpha6beta4 function. The structure reveals a novel interdomain interface and candidate protein-binding sites, including a large acidic cleft formed from the surfaces of both domains and a prominent loop that is reminiscent of the RGD integrin-binding loop of fibronectin. This is the first crystal structure of either a hemidesmosome component or an integrin cytoplasmic domain, and it will enable the intracellular functions of alpha6beta4 to be dissected at the atomic level.

Selected figure(s)

Figure 3.
Figure 3 Stereo close-up of the interdomain interface. Selected residues are shown in ball-and-stick form; hydrogen bonds between linker side chains and domain loops are indicated by dashed lines. The view is rotated by 180° about a vertical axis compared with Figure 1B.

Figure 5.
Figure 5 Electron density maps of the C–C' loop of domain 2. The refined structure of the loop is shown in ball-and-stick form. (A) Experimental solvent flattened map at 2.8 Å resolution, contoured at 1 . (B) 2F[o]-F[c] map with phases calculated from the final model at 2.15 Å, contoured at 1 .

The above figures are reprinted from an Open Access publication published by Macmillan Publishers Ltd: EMBO J (1999, 18, 4087-4095) copyright 1999.

Figures were selected by an automated process.