VIRULENT SHIGELLA CODES FOR A SOLUBLE APYRASE - IDENTIFICATION, CHARACTERIZATION AND CLONING OF TIME GENE

Citation
T. Bhargava et al., VIRULENT SHIGELLA CODES FOR A SOLUBLE APYRASE - IDENTIFICATION, CHARACTERIZATION AND CLONING OF TIME GENE, Current Science, 68(3), 1995, pp. 293-300
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary Sciences
Journal title
ISSN journal
0011-3891
Volume
68
Issue
3
Year of publication
1995
Pages
293 - 300
Database
ISI
SICI code
0011-3891(1995)68:3<293:VSCFAS>2.0.ZU;2-7
Abstract
Periplasmic fractions of virulent Shigella spp. and related enteroinva sive Escherichia coil showed a specific ATP hydrolysing activity in th e presence of 10 mM EDTA. Analysis of the reaction products using the purified enzyme of 25 kDa, showed that ATP was hydrolysed sequentially to ADP and AMP through release of inorganic phosphate, The enzyme was , therefore, identified as ATP diphosphohydrolase or apyrase (EC 3.6.1 .5), The apyrase gene (apy) encoded by the megaplasmid of Shigella fle xneri 2a was cloned and expressed in E. coil, Analysis of the expresse d proteins confirmed that both the ATPase and ADPase activities are as sociated with a single gene product, The in vitro catalytic activity o f the virulence-associated apyrase of Shigella could explain some of t he early metabolic events that fake place following the invasion of th e host cells by Shigella, viz, a drop in cellular ATP level, mitochond rial damage, and general disruption of energy metabolism, These result s suggest that apyrase of Shigella may be a general cytotoxin involved directly or indirectly in the actual killing of the host cells.