2LL3 image
Entry Detail
PDB ID:
2LL3
Keywords:
Title:
The solution structure of TgMIC4 apple-5 domain
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2011-10-26
Release Date:
2012-04-04
Method Details:
Experimental Method:
Conformers Calculated:
10
Conformers Submitted:
10
Selection Criteria:
structures with the lowest energy
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Micronemal protein 4
Chain IDs:A
Chain Length:82
Number of Molecules:1
Biological Source:Toxoplasma gondii
Ligand Molecules
Primary Citation
Galactose Recognition by the Apicomplexan Parasite Toxoplasma gondii.
J.Biol.Chem. 287 16720 16733 (2012)
PMID: 22399295 DOI: 10.1074/jbc.M111.325928

Abstact

Toxosplasma gondii is the model parasite of the phylum Apicomplexa, which contains numerous obligate intracellular parasites of medical and veterinary importance, including Eimeria, Sarcocystis, Cryptosporidium, Cyclospora, and Plasmodium species. Members of this phylum actively enter host cells by a multistep process with the help of microneme protein (MIC) complexes that play important roles in motility, host cell attachment, moving junction formation, and invasion. T. gondii (Tg)MIC1-4-6 complex is the most extensively investigated microneme complex, which contributes to host cell recognition and attachment via the action of TgMIC1, a sialic acid-binding adhesin. Here, we report the structure of TgMIC4 and reveal its carbohydrate-binding specificity to a variety of galactose-containing carbohydrate ligands. The lectin is composed of six apple domains in which the fifth domain displays a potent galactose-binding activity, and which is cleaved from the complex during parasite invasion. We propose that galactose recognition by TgMIC4 may compromise host protection from galectin-mediated activation of the host immune system.

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Primary Citation of related structures