PDBsum entry 1ijk

Blood clotting/toxin

PDB id: 1ijk

Contents

Protein chains

199 a.a. *

133 a.a. *

119 a.a. *

Waters ×94

* Residue conservation analysis

PDB id:

1ijk

Name:

Blood clotting/toxin

Title:

The von willebrand factor mutant (i546v) a1 domain-botrocetin complex

Structure:

Von willebrand factor. Chain: a. Fragment: a1 domain. Engineered: yes. Mutation: yes. Botrocetin. Chain: b. Fragment: a-subunit. Botrocetin.

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 562. Bothrops jararaca. Jararaca. Organism_taxid: 8724. Secretion: venom.

Biol. unit:

Trimer (from PQS)

Resolution:

2.60Å R-factor: 0.219 R-free: 0.279

Authors:

K.Fukuda,T.A.Doggett,L.A.Bankston,M.A.Cruz,T.G.Diacovo,R.C.Liddington

Key ref:

K.Fukuda et al. (2002). Structural basis of von Willebrand factor activation by the snake toxin botrocetin. Structure, 10, 943-950. PubMed id: 12121649 DOI: 10.1016/S0969-2126(02)00787-6

Date:

26-Apr-01 Release date: 10-Jul-02

Protein chain

P04275  (VWF_HUMAN) -  von Willebrand factor from Homo sapiens

Seq: 2813 a.a.

Struc: 199 a.a.*

Protein chain

P22029  (SLEA_BOTJA) -  Snaclec botrocetin subunit alpha from Bothrops jararaca

Seq: 133 a.a.

Struc: 133 a.a.

Protein chain

P22030  (SLEB_BOTJA) -  Snaclec botrocetin subunit beta from Bothrops jararaca

Seq: 125 a.a.

Struc: 119 a.a.

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

DOI no: 10.1016/S0969-2126(02)00787-6

Structure 10:943-950 (2002)

PubMed id: 12121649

Structural basis of von Willebrand factor activation by the snake toxin botrocetin.

K.Fukuda, T.A.Doggett, L.A.Bankston, M.A.Cruz, T.G.Diacovo, R.C.Liddington.

ABSTRACT

The A1 domain of von Willebrand factor (vWF) mediates platelet adhesion to sites of vascular injury by binding to the platelet receptor glycoprotein Ib (GpIb), an interaction that is regulated by hydrodynamic shear forces. The GpIb binding surface of A1 is distinct from a regulatory region, suggesting that ligand binding is controlled allosterically. Here we report the crystal structures of the "gain-of-function" mutant A1 domain (I546V) and its complex with the exogenous activator botrocetin. We show that botrocetin switches the mutant A1 back toward the wild-type conformation, suggesting that affinity is enhanced by augmenting the GpIb binding surface rather than through allosteric control. Functional studies of platelet adhesion under flow further suggest that the activation mechanism is distinct from that of the gain-of-function mutation.

Selected figure(s)

Figure 3.
Figure 3. Structure of the A1-Botrocetin Complex(A) Stereo view (Ca tracing) of the complex. The current model includes 199 residues from 502 to 700 of the mutant A1 domain, 133 (119) residues of the a (b) subunits of botrocetin, and 94 water molecules. There is no electron density for the loop (residues 55-60 in the b subunit). The A1 domain is in blue; the a and b subunits of botrocetin are in pink and green, respectively. Gain-of-function mutations are shown as blue balls; loss-of-function mutations are shown in red; loss of botrocetin binding mutations are shown in yellow. The I546V mutation site is shown as a green ball.(B) Space-filling model of the complex with mutation sites indicated; same view as in (A). The NMC-4 antibody (V[H]-V[L] dimer) is shown as a semitransparent molecular surface.(C) Electrostatic surface potential contoured from -15 (red) to +15 (blue) kT e^ -1. The figure was made using RASTER3D [30] and GRASP [32].

The above figure is reprinted by permission from Cell Press: Structure (2002, 10, 943-950) copyright 2002.

Figure was selected by an automated process.