PDBsum entry 1uos

Sugar binding protein

PDB id: 1uos

Contents

Protein chains

133 a.a. *

124 a.a. *

Waters ×320

* Residue conservation analysis

PDB id:

1uos

Name:

Sugar binding protein

Title:

The crystal structure of the snake venom toxin convulxin

Structure:

Convulxin alpha. Chain: a, c. Synonym: cvx alpha. Convulxin beta. Chain: b, d. Synonym: cvx beta

Source:

Crotalus durissus terrificus. South american rattlesnake. Organism_taxid: 8732. Organism_taxid: 8732

Biol. unit:

Octamer (from PDB file)

Resolution:

2.70Å R-factor: 0.235 R-free: 0.263

Authors:

T.Batuwangala,M.Leduc,J.M.Gibbins,C.Bon,E.Y.Jones

Key ref:

T.Batuwangala et al. (2004). Structure of the snake-venom toxin convulxin. Acta Crystallogr D Biol Crystallogr, 60, 46-53. PubMed id: 14684891 DOI: 10.1107/S0907444903021620

Date:

22-Sep-03 Release date: 14-Oct-03

Protein chains

O93426  (SLA_CRODU) -  Snaclec convulxin subunit alpha from Crotalus durissus terrificus

Seq: 158 a.a.

Struc: 133 a.a.

Protein chains

O93427  (SLB_CRODU) -  Snaclec convulxin subunit beta from Crotalus durissus terrificus

Seq: 148 a.a.

Struc: 124 a.a.

DOI no: 10.1107/S0907444903021620

Acta Crystallogr D Biol Crystallogr 60:46-53 (2004)

PubMed id: 14684891

Structure of the snake-venom toxin convulxin.

T.Batuwangala, M.Leduc, J.M.Gibbins, C.Bon, E.Y.Jones.

ABSTRACT

Snake venoms contain a number of proteins that interact with components of the haemostatic system that promote or inhibit events leading to blood-clot formation. The snake-venom protein convulxin (Cvx) binds glycoprotein (GP) VI, the platelet receptor for collagen, and triggers signal transduction. Here, the 2.7 A resolution crystal structure of Cvx is presented. In common with other members of this snake-venom protein family, Cvx is an alphabeta-heterodimer and conforms to the C-type lectin-fold topology. Comparison with other family members allows a set of Cvx residues that form a concave surface to be putatively implicated in GPVI binding. Unlike other family members, with the exception of flavocetin-A (FL-A), Cvx forms an (alphabeta)(4) tetramer. This oligomeric structure is consistent with Cvx clustering GPVI molecules on the surface of platelets and as a result promoting signal transduction activity. The Cvx structure and the location of the putative binding sites suggest a model for this multimeric signalling assembly.

Selected figure(s)

Figure 3.
Figure 3 Analysis of the concave surface of Cvx. (a) Surface representation of the Cvx tetramer. (b) Orientation of the concave surface relative to the rest of the molecule. - and -subunits are coloured blue and red, respectively. The van der Waals surface of the -heterodimer is depicted in transparent grey and the concave surface with a transparent brown tint. Relative orientations of views are given. (c) Close-up view of the concave surface of the -heterodimer. Residues contributing to charged patches are indicated. (d) Schematic representation of the Cvx tetramer interaction with protein ligand at the cell surface. The Cvx tetramer is depicted as in Fig. 1-(a) with a 120° rotation about the horizontal. Ligand molecules interacting at each concave surface are depicted as transparent gold spheres. The cell surface is depicted in grey.

Figure 4.
Figure 4 Homology modelling and analysis of GPVI. (a) Sequence alignment between GPVI and Lir-1. (b) C^ trace of the GPVI model in coil representation; side chains of residues contributing to charged patches are drawn in ball-and-stick representation. (c) Surface representation of GPVI model showing distribution of electrostatic potential coloured in blue (positive) and red (negative) viewed in three orientations. The starting orientation is as in (b).

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2004, 60, 46-53) copyright 2004.

Figures were selected by an automated process.