PDBsum entry 1l7c

Cell adhesion

PDB id: 1l7c

Contents

Protein chains

240 a.a. *

Waters ×90

* Residue conservation analysis

PDB id:

1l7c

Name:

Cell adhesion

Title:

Alpha-catenin fragment, residues 385-651

Structure:

Alpha e-catenin. Chain: a, b, c. Fragment: residues 385-651. Synonym: alpha-1 catenin, cadherin-associated protein. Engineered: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

Biol. unit:

Trimer (from PQS)

Resolution:

2.50Å R-factor: 0.238 R-free: 0.273

Authors:

S.Pokutta,F.Drees,Y.Takai,W.J.Nelson,W.I.Weis

Key ref:

S.Pokutta et al. (2002). Biochemical and structural definition of the l-afadin- and actin-binding sites of alpha-catenin. J Biol Chem, 277, 18868-18874. PubMed id: 11907041 DOI: 10.1074/jbc.M201463200

Date:

14-Mar-02 Release date: 19-Jun-02

Protein chains

P26231  (CTNA1_MOUSE) -  Catenin alpha-1 from Mus musculus

Seq: 906 a.a.

Struc: 240 a.a.

DOI no: 10.1074/jbc.M201463200

J Biol Chem 277:18868-18874 (2002)

PubMed id: 11907041

Biochemical and structural definition of the l-afadin- and actin-binding sites of alpha-catenin.

S.Pokutta, F.Drees, Y.Takai, W.J.Nelson, W.I.Weis.

ABSTRACT

alpha-Catenin is an integral component of adherens junctions, where it links cadherins to the actin cytoskeleton. alpha-Catenin is also required for the colocalization of the nectin/afadin/ponsin adhesion system to adherens junctions, and it specifically associates with the nectin-binding protein afadin. A proteolytic fragment of alpha-catenin, residues 385-651, contains the afadin-binding site. The three-dimensional structure of this fragment comprises two side-by-side four-helix bundles, both of which are required for afadin binding. The alpha-catenin fragment 385-651 binds afadin more strongly than the full-length protein, suggesting that the full-length protein harbors a cryptic binding site for afadin. Comparison of the alpha-catenin 385-651 structure with the recently solved structure of the alpha-catenin M-fragment (Yang, J., Dokurno, P., Tonks, N. K., and Barford, D. (2001) EMBO J. 20, 3645-3656) reveals a surprising flexibility in the orientation of the two four-helix bundles. alpha-Catenin and the actin-binding protein vinculin share sequence and most likely structural similarity within their actin-binding domains. Despite this homology, actin binding requires additional sequences adjacent to this region.

Selected figure(s)

Figure 2.
Fig. 2. Oligomerization of -catenin 385-651 and its N- and C-terminal subdomains. Fragments at the indicated concentrations were incubated with a 30-fold excess of cross-linker. For the two amine-reactive cross-linking reagents BS3 and DMS with spacer arms of 11.4 and 11.0 Å, respectively, different cross-linking efficiency was observed. Higher cross-linking efficiency results are shown here and were obtained with DMS in the case of -catenin 507-632 and BS3 for -catenin 385-651 and -catenin 385-507. The first lane for the -catenin 385-651 fragment shows a sample in the absence of cross-linker. Molecular mass markers are indicated on the left of each gel, and apparent molecular mass of the fragments and cross-linking products are shown on the right.

Figure 4.
Fig. 4. Interaction of -catenin ( -cat) with F-actin. A, schematic representation of -catenin and the constructs used in the binding assay. Vinculin homology regions are shown in dark gray. B, binding to F-actin was examined by cosedimentation. Assuming a binding ratio of protein:monomeric actin of 1:7, all -catenin constructs were added in excess. The supernatant (S) containing the unbound protein and the pellet (P) containing F-actin and bound protein are shown for each sample. Molecular mass markers are indicated on the left.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2002, 277, 18868-18874) copyright 2002.

Figures were selected by an automated process.