A structure-to-function approach was undertaken to gain insights into the potential function of the 32-kDa membrane lipoprotein (Tp32) of Treponema, pallidum, the syphilis bacterium. The crystal structure of rTp32 (determined at a resolution of 1.85 A) shows that the organization of rTp32 is similar to other periplasmic ligand-binding proteins (PLBPs), in that it consists of two α/β domains, linked by two crossovers, with a binding pocket between them. In the pocket, a molecule of L-methionine was detected in the electron density map. Residues from both domains interact with the ligand. One of the crossover regions is comprised of a 310-helix, a feature not typical in other ligand-binding proteins. Sequence comparison shows strong similarity to other hypothetical methionine-bmding proteins. Together, the data support the notion that rTp32 is a component of a periplasmic methionine uptake transporter system in T. pallidum.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Biological Chemistry|
|State||Published - Dec 31 2004|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology