title: The bacA gene of Escherichia coli encodes an undecaprenyl pyrophosphate phosphatase activity.
abstract: The bacA gene, the overexpression of which results in bacitracin resistance, was inactivated and shown to be non-essential for growth of Escherichia coli. It was proposed earlier that the bacA gene product may confer resistance to the antibiotic by phosphorylation of undecaprenol (Cain, B. D., Norton, P. J., Eubanks, W., Nick, H. S., and Allen, C. M. (1983) J. Bacteriol. 175, 3784-3789). In the present work, this extremely hydrophobic membrane protein was overproduced and purified to near homogeneity. The analysis of its catalytic properties clearly demonstrated that the purified BacA protein exhibited undecaprenyl pyrophosphate phosphatase activity but not undecaprenol phosphokinase activity. This finding was perfectly consistent with the mechanism of action of bacitracin that consists in the sequestration of undecaprenyl pyrophosphate, the BacA enzyme substrate. The level of undecaprenyl pyrophosphate phosphatase was increased by 280-fold in cells carrying bacA on a multicopy expression plasmid. It was decreased by approximately 75% but was not completely abolished in a bacA disruption mutant, suggesting that BacA is the main E. coli undecaprenyl pyrophosphate phosphatase but that other protein(s) exhibiting such an activity should exist to account for the residual activity and viability of the mutant strain. This is the first gene encoding undecaprenyl pyrophosphate phosphatase identified to date. Considering its newly identified function, we propose to rename the bacA gene uppP.
authors.affiliation: Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619 CNRS, Université Paris-Sud, Bâtiment 430, 91405 Orsay, France.
authors.forename: Meriem
authors.initials: M
authors.lastname: El Ghachi
authors.forename: Ahmed
authors.initials: A
authors.lastname: Bouhss
authors.forename: Didier
authors.initials: D
authors.lastname: Blanot
authors.forename: Dominique
authors.initials: D
authors.lastname: Mengin-Lecreulx
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism; D001414:Bacitracin / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002384:Catalysis; D002462:Cell Membrane / Q000378:metabolism; D002855:Chromatography, Thin Layer; D003593:Cytoplasm / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics*; D026901:Membrane Transport Proteins / Q000235:genetics; D008954:Models, Biological; D009154:Mutation; D010641:Phenotype; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis / Q000235:genetics*; D010957:Plasmids / Q000378:metabolism; D011106:Polyisoprenyl Phosphates / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors; D014166:Transferases / Q000378:metabolism; D017855:Transferases (Other Substituted Phosphate Groups)
chemical_list: D001426:Bacterial Proteins; D003902:Detergents; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D011106:Polyisoprenyl Phosphates; C082397:bacA protein, Rhizobium meliloti; D001414:Bacitracin; C088139:undecaprenyl pyrophosphate; D014166:Transferases; D017855:Transferases (Other Substituted Phosphate Groups); C079803:mraY protein, Bacteria; C488524:BacA protein, E coli; D010744:Phosphoric Monoester Hydrolases