PDBsum entry 1w3f

Toxin/lectin

PDB id: 1w3f

Contents

Protein chain

313 a.a. *

Ligands

NDG-GAL

GOL ×5

Waters ×129

* Residue conservation analysis

PDB id:

1w3f

Name:

Toxin/lectin

Title:

Crystal structure of the hemolytic lectin from the mushroom laetiporus sulphureus complexed with n-acetyllactosamine in the gamma motif

Structure:

Hemolytic lectin from laetiporus sulphureus. Chain: a

Source:

Laetiporus sulphureus. Organism_taxid: 5630

Biol. unit:

Hexamer (from PDB file)

Resolution:

2.58Å R-factor: 0.231 R-free: 0.272

Authors:

J.M.Mancheno,H.Tateno,I.J.Goldstein,M.Martinez-Ripoll,J.A.Hermoso

Key ref:

J.M.Mancheño et al. (2005). Structural analysis of the Laetiporus sulphureus hemolytic pore-forming lectin in complex with sugars. J Biol Chem, 280, 17251-17259. PubMed id: 15687495 DOI: 10.1074/jbc.M413933200

Date:

15-Jul-04 Release date: 01-Feb-05

Protein chain

Q7Z8V1  (Q7Z8V1_9APHY) -  Hemolytic lectin LSLa from Laetiporus sulphureus

Seq: 315 a.a.

Struc: 313 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1074/jbc.M413933200

J Biol Chem 280:17251-17259 (2005)

PubMed id: 15687495

Structural analysis of the Laetiporus sulphureus hemolytic pore-forming lectin in complex with sugars.

J.M.Mancheño, H.Tateno, I.J.Goldstein, M.Martínez-Ripoll, J.A.Hermoso.

ABSTRACT

LSL is a lectin produced by the parasitic mushroom Laetiporus sulphureus, which exhibits hemolytic and hemagglutinating activities. Here, we report the crystal structure of LSL refined to 2.6-A resolution determined by the single isomorphous replacement method with the anomalous scatter (SIRAS) signal of a platinum derivative. The structure reveals that LSL is hexameric, which was also shown by analytical ultracentrifugation. The monomeric protein (35 kDa) consists of two distinct modules: an N-terminal lectin module and a pore-forming module. The lectin module has a beta-trefoil scaffold that bears structural similarities to those present in toxins known to interact with galactose-related carbohydrates such as the hemagglutinin component (HA1) of the progenitor toxin from Clostridium botulinum, abrin, and ricin. On the other hand, the C-terminal pore-forming module (composed of domains 2 and 3) exhibits three-dimensional structural resemblances with domains 3 and 4 of the beta-pore-forming toxin aerolysin from the Gram-negative bacterium Aeromonas hydrophila, and domains 2 and 3 from the epsilon-toxin from Clostridium perfringens. This finding reveals the existence of common structural elements within the aerolysin-like family of toxins that could be directly involved in membrane-pore formation. The crystal structures of the complexes of LSL with lactose and N-acetyllactosamine reveal two dissacharide-binding sites per subunit and permits the identification of critical residues involved in sugar binding.

Selected figure(s)

Figure 1.
FIG. 1. Three-dimensional structure and topology diagram of LSL. A, ribbon model of monomeric LSL. The figure is colored from the N to C terminus in a progression from blue to red via green. Numbers 1-23 indicate the corresponding -strands and H1-H7 are the single-turn 3[10] helices. B, topology diagram of LSL. -Strands and 3[10] helices are represented by arrows and cylinders, respectively. The starting and ending sequence numbers for each secondary structural element are given. The lectin module is represented in green and the pore-forming module in brown. A was prepared with BOBSCRIPT (52) and RASTER3D (53).

Figure 3.
FIG. 3. Lactose and N-acetyllactosamine binding to the lectin module of LSL. A, structure of the Lac molecule bound to the -motif of LSL. B, three-dimensional structure of LacNAc bound to the -motif of LSL. The models show the F[o] - F[c] electron density maps contoured at 2.5 around the Lac molecule initially calculated without including the disaccharide. C, LacNAc bound to the -motif. The F[o] - F[c] electron density map contoured at 3 calculated without including the disaccharide is shown in blue around the bound carbohydrate. Broken lines indicate hydrogen bonds between sugar and protein residues. Color coding of secondary structure elements: -motif, blue; -motif, red, -motif, green. D, molecular surface of the -trefoil scaffold, with the LacNAc molecules (as stick models) bound to the - and -sites. The surface is colored according to the electrostatic potential, blue for positive and red for negative. E, structure of Lac bound to one binding site in ricin B-chain (Protein Data Bank code 2AAI [PDB] ; Ref. 40). A-C were prepared with MOLSCRIPT (54) and RASTER3D (53); the molecular surface was built with the program GRASP (55).

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2005, 280, 17251-17259) copyright 2005.

Figures were selected by the author.