A novel role for protein-tyrosine kinase Etk from Escherichia coli K-12 related to polymyxin resistance.

S. Lacour (1) , P. Doublet (1) , B. Obadia (1) , Aj Cozzone (1) , C. Grangeasse (1)

1 IBCP - Institut de biologie et chimie des protéines [Lyon]

The role of protein-tyrosine kinases in bacterial polymyxin resistance was assessed by both genetic and biochemical approaches. Each of the two genes, wzc and etk, encoding protein-tyrosine kinases in Escherichia coli, was knocked out by using the PCR-based method of one-step inactivation of chromosomal genes, and the corresponding mutant strain was assayed in each case for resistance to different concentrations of polymyxin B by measuring the percentage of surviving cells. The resistance of a double knock-out wzc-etk-mutant was also analyzed and complementation experiments were performed by checking the effect of plasmid vectors expressing either Wzc or Etk. Our results concurred in showing that protein-kinase Wzc is not essential for polymyxin resistance, whereas protein-kinase Etk appears to play a key role in such antibiotic resistance. This newly found specific function of Etk reinforces the concept that protein-tyrosine kinases are involved in distinct facets of bacterial physiology.The role of protein-tyrosine kinases in bacterial polymyxin resistance was assessed by both genetic and biochemical approaches. Each of the two genes, wzc and etk, encoding protein-tyrosine kinases in Escherichia coli, was knocked out by using the PCR-based method of one-step inactivation of chromosomal genes, and the corresponding mutant strain was assayed in each case for resistance to different concentrations of polymyxin B by measuring the percentage of surviving cells. The resistance of a double knock-out wzc-etk-mutant was also analyzed and complementation experiments were performed by checking the effect of plasmid vectors expressing either Wzc or Etk. Our results concurred in showing that protein-kinase Wzc is not essential for polymyxin resistance, whereas protein-kinase Etk appears to play a key role in such antibiotic resistance. This newly found specific function of Etk reinforces the concept that protein-tyrosine kinases are involved in distinct facets of bacterial physiology.

Domaines: Biochimie, Biologie Moléculaire

S. Lacour, P. Doublet, B. Obadia, Aj Cozzone, C. Grangeasse. A novel role for protein-tyrosine kinase Etk from Escherichia coli K-12 related to polymyxin resistance.. Res Microbiol, 2006, xxx, pp.637-641. ⟨hal-00314516⟩