PDBsum entry 1f4x

Immune system

PDB id: 1f4x

Contents

Protein chains

210 a.a. *

216 a.a. *

Ligands

MGS

Waters ×57

* Residue conservation analysis

PDB id:

1f4x

Name:

Immune system

Title:

Crystal structure of an anti-carbohydrate antibody directed against vibrio cholerae o1 in complex with antigen

Structure:

Antibody s-20-4, fab fragment, light chain. Chain: l. Antibody s-20-4, fab fragment, heavy chain. Chain: h

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Secretion: ascites. Secretion: ascites

Biol. unit:

Dimer (from PQS)

Resolution:

2.30Å R-factor: 0.185 R-free: 0.250

Authors:

P.M.Alzari,H.Souchon

Key ref:

S.Villeneuve et al. (2000). Crystal structure of an anti-carbohydrate antibody directed against Vibrio cholerae O1 in complex with antigen: molecular basis for serotype specificity. Proc Natl Acad Sci U S A, 97, 8433-8438. PubMed id: 10880560 DOI: 10.1073/pnas.060022997

Date:

10-Jun-00 Release date: 02-Aug-00

Protein chain

No UniProt id for this chain

Struc: 210 a.a.

Protein chain

No UniProt id for this chain

Struc: 216 a.a.

DOI no: 10.1073/pnas.060022997

Proc Natl Acad Sci U S A 97:8433-8438 (2000)

PubMed id: 10880560

Crystal structure of an anti-carbohydrate antibody directed against Vibrio cholerae O1 in complex with antigen: molecular basis for serotype specificity.

S.Villeneuve, H.Souchon, M.M.Riottot, J.C.Mazie, P.Lei, C.P.Glaudemans, P.Kovác, J.M.Fournier, P.M.Alzari.

ABSTRACT

The crystal structure of the murine Fab S-20-4 from a protective anti-cholera Ab specific for the lipopolysaccharide Ag of the Ogawa serotype has been determined in its unliganded form and in complex with synthetic fragments of the Ogawa O-specific polysaccharide (O-SP). The upstream terminal O-SP monosaccharide is shown to be the primary antigenic determinant. Additional perosamine residues protrude outwards from the Ab surface and contribute only marginally to the binding affinity and specificity. A complementary water-excluding hydrophobic interface and five Ab-Ag hydrogen bonds are crucial for carbohydrate recognition. The structure reported here explains the serotype specificity of anti-Ogawa Abs and provides a rational basis toward the development of a synthetic carbohydrate-based anti-cholera vaccine.

Selected figure(s)

Figure 2.
Fig. 2. Final (2F[o] F[c]) electron density maps contoured at 1.5 for the Ogawa monosaccharide and disaccharide fragments bound to the Ab binding cleft. The methyl group at the O-2 position of the terminal perosamine residue is indicated. Figure produced with the program O (26).

Figure 4.
Fig. 4. Protein-carbohydrate interactions. The molecular surface (colored according to charge) for the Fab fragment of S-20-4 with the (a) monosaccharide and (b) disaccharide ligands. (c) Close view of the bound monosaccharide, with the sugar ring facing a central hydrophobic pocket and the tetronic acid moiety occupying a shallow cavity formed by residues from the Ab heavy chain. (d) Intermolecular hydrogen bonding interactions in the Fab-disaccharide complex. [The hydrogen bond between the carbonyl group of the upstream terminal sugar residue (arrow) and the main chain NH group at position H98 is not shown.] Figure produced with the program GRASP (41).

Figures were selected by the author.