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A polyphosphate kinase 1 (ppk1) mutant of Pseudomonas aeruginosa exhibits multiple ultrastructural and functional defects

Fraley, Cresson D., Rashid, M. Harunur, Lee, Sam S.K., Gottschalk, Rebecca, Harrison, Janine, Wood, Pauline J., Brown, Michael R.W., Kornberg, Arthur
Proceedings of the National Academy of Sciences of the United States of America 2007 v.104 no.9 pp. 3526-3531
Escherichia coli, Pseudomonas aeruginosa, bacteria, biofilm, carbenicillin, mutants, quorum sensing, virulence
Pseudomonas aeruginosa, of medical, environmental, and industrial importance, depends on inorganic polyphosphate (poly P) for a wide range of functions, especially survival. Mutants of PAO1 lacking poly P kinase 1, PPK1, the enzyme responsible for most poly P synthesis in Escherichia coli and other bacteria, are defective in motility, quorum sensing, biofilm formation, and virulence. We describe here multiple defects in the ppk1 mutant PAOM5, including a striking compaction of the nucleoid, distortion of the cell envelope, lack of planktonic motility and exopolymer production, and susceptibility to the β-lactam antibiotic carbenicillin as well as desiccation. We propose that P. aeruginosa with reduced poly P levels undergoes ultrastructural changes that contribute to profound deficiencies in cellular functions.