ISSN:
1399-0047
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Pneumolysin is a virulence factor from Streptococcus pneumoniae, a Gram-positive bacterial pathogen which causes human infections with a severe impact on mortality and morbidity worldwide. The enzyme belongs to a group of cholesterol-dependent cytolysins and interacts with its cholesterol receptor on target cells, leading to pneumolysin insertion into target-cell membranes and subsequently to pore formation and cell lysis. Pneumolysin has been overexpressed, purified and crystallized for X-ray diffraction studies. Crystals have been obtained in the presence of cholesterol in an effort to produce a three-dimensional structure of pneumolysin in its fully functional form with the enzyme bound to its activator. This is the first report of the crystallization of a cholesterol-dependent cytolysin in the presence of bound cholesterol. The vapor-diffusion method using ammonium sulfate as a precipitation agent was used to grow crystals in the presence of n-octyl-β-D-glucopyranoside and phosphatidylcholine. Crystals of this 53 kDa molecule complexed with cholesterol diffracted X-rays to 3.3 Å. The crystal unit cell has parameters a = b = 191.45, c = 66.16 Å, α = β = 90.0, γ = 120° and belongs to the trigonal space group P3. The determination of the three-dimensional structure of this pneumococcal cytolysin is in progress.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0907444900010143
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