PMID:11940590
| Citation |
Renshaw, PS, Panagiotidou, P, Whelan, A, Gordon, SV, Hewinson, RG, Williamson, RA and Carr, MD (2002) Conclusive evidence that the major T-cell antigens of the Mycobacterium tuberculosis complex ESAT-6 and CFP-10 form a tight, 1:1 complex and characterization of the structural properties of ESAT-6, CFP-10, and the ESAT-6*CFP-10 complex. Implications for pathogenesis and virulence. J. Biol. Chem. 277:21598-603 |
|---|---|
| Abstract |
The proteins ESAT-6 and CFP-10 have been shown to be secreted by Mycobacterium tuberculosis and Mycobacterium bovis cells, to be potent T-cell antigens, and to have a clear but as yet undefined role in tuberculosis pathogenesis. We have successfully overexpressed both ESAT-6 and CFP-10 in Escherichia coli and developed efficient purification schemes. Under in vivo-like conditions, a combination of fluorescence, circular dichroism, and nuclear magnetic resonance spectroscopy have shown that ESAT-6 contains up to 75% helical secondary structure, but little if any stable tertiary structure, and exists in a molten globule-like state. In contrast, CFP-10 was found to form an unstructured, random coil polypeptide. An exciting discovery was that ESAT-6 and CFP-10 form a tight, 1:1 complex, in which both proteins adopt a fully folded structure, with about two-thirds of the backbone in a regular helical conformation. This clearly suggests that ESAT-6 and CFP-10 are active as the complex and raises the interesting question of whether other ESAT-6/CFP-10 family proteins (22 paired genes in M. tuberculosis) also form tight, 1:1 complexes, and if so, is this limited to their genome partner, or is there scope for wider interactions within the protein family, which could provide greater functional flexibility? |
| Links |
PubMed Online version:10.1074/jbc.M201625200 |
| Keywords |
Antigens/metabolism; Antigens, Bacterial/chemistry; Antigens, Bacterial/metabolism; Bacterial Proteins/chemistry; Bacterial Proteins/metabolism; Circular Dichroism; Electrophoresis, Polyacrylamide Gel; Escherichia coli/metabolism; Genetic Vectors; Guanidine/pharmacology; Histidine/chemistry; Magnetic Resonance Spectroscopy; Mycobacterium bovis/metabolism; Mycobacterium tuberculosis/metabolism; Parasympathomimetics/pharmacology; Phylogeny; Protein Binding; Protein Denaturation; Protein Structure, Tertiary; Spectrometry, Fluorescence; T-Lymphocytes/immunology; T-Lymphocytes/metabolism; Ultraviolet Rays |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.