Insights into pneumococcal invasiveness: The role of phosphorylcholine esterase, Pce
Project Leader: Juan A. Hermoso


The crystal structure of the pneumococcal phosphorylcholine esterase, Pce (602 amino acids), revelaed Pce could selectively modify the distribution of the phosphoryl choline moieties on the bacterial surface. Thus Pce should impair the ability of human defense system to efficiently bind the bacteria, and would provide a mechanism for pneumococci escaping the immune attack.

Besides, we have verified the ability of Pce to hydrolyze PAF (human platelet-activating factor) a pivotal first messenger of the inflammatory processes suggesting that this enzyme has other functions during infection. This finding opens a new scenario on the role that Pce may play in the mechanism of pneumococcal adherence and invasiveness.


Insights into pneumococcal pathogenesis from crystal structure of the modular teichoic acid phosphorylcholine esterase Pce
Hermoso, J., Lagartera, L., Gonzalez, A., Stelter, M., Garcia, P., Martinez-Ripoll, M., Garcia, J.L. and Menendez, M.
Nature Structural and Molecular Biology (2005) 12, 533-538  (doi:10.1038/nsmb940)

Pneumococcal phosphorylcholine esterase, Pce, contains a zinc binuclear center that is essential for substrate binding and catalysis
L. Lagartera, A. González, J. A. Hermoso, J. L. Saíz, P. García, J. L. García and M. Menéndez
Protein Science (2005) 14, 3013-3024  (doi:10.1110/ps.051575005)

Enjoy the short movie shown below, explaining how Pce is used by pneumococcus for camouflage purposes...