Microcin J25 has a dual and independent mechanism of action in Escherichia coli : RNA polymerase and superoxide production stimulation.

AUGUSTO BELLOMIO; PAULA A. VINCENT; BEATRIZ F. DE ARCURI; RICARDO N. FARÍAS; ROBERTO D. MORERO

JOURNAL OF BACTERIOLOGY

ASM press

Año: 2007 vol. 189 p. 4180 - 4186

0021-9193

Microcin J25 (MccJ25) uptake by Escherichia coli requires the outer membrane receptor FhuA and the inner membrane proteins TonB, ExbD, ExbB, and SbmA. MccJ25 appears to have two intracellular targets: (i) RNA polymerase (RNAP), which has been described in E. coli and Salmonella enterica serovars, and (ii) the respiratory chain, reported only in S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica and (ii) the respiratory chain, reported only in S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica inner membrane proteins TonB, ExbD, ExbB, and SbmA. MccJ25 appears to have two intracellular targets: (i) RNA polymerase (RNAP), which has been described in E. coli and Salmonella enterica serovars, and (ii) the respiratory chain, reported only in S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica and (ii) the respiratory chain, reported only in S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica Escherichia coli requires the outer membrane receptor FhuA and the inner membrane proteins TonB, ExbD, ExbB, and SbmA. MccJ25 appears to have two intracellular targets: (i) RNA polymerase (RNAP), which has been described in E. coli and Salmonella enterica serovars, and (ii) the respiratory chain, reported only in S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica and (ii) the respiratory chain, reported only in S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica E. coli and Salmonella enterica serovars, and (ii) the respiratory chain, reported only in S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica the observed difference between the actions of microcin on the respiratory chain in E. coli and S. enterica S. enterica serovars. In the current study, it is shown that the observed difference between the actions of microcin on the respiratory chain in E. coli and S. entericaE. coli and S. enterica is due to the relatively low microcin uptake via the chromosomally encoded FhuA. Higher expression by a plasmid-encoded FhuA allowed greater uptake of MccJ25 by E. coli strains and the consequent inhibition of oxygen consumption. The two mechanisms, inhibition of RNAP and oxygen consumption, are independent of each other. Further analysis revealed for the first time that MccJ25 stimulates the production of reactive oxygen species (O2ÿ
) in bacterial cells, which could be the main reason for the damage produced on the membrane respiratory chain. on the membrane respiratory chain. of oxygen consumption. The two mechanisms, inhibition of RNAP and oxygen consumption, are independent of each other. Further analysis revealed for the first time that MccJ25 stimulates the production of reactive oxygen species (O2ÿ
) in bacterial cells, which could be the main reason for the damage produced on the membrane respiratory chain. on the membrane respiratory chain. E. coli strains and the consequent inhibition of oxygen consumption. The two mechanisms, inhibition of RNAP and oxygen consumption, are independent of each other. Further analysis revealed for the first time that MccJ25 stimulates the production of reactive oxygen species (O2ÿ
) in bacterial cells, which could be the main reason for the damage produced on the membrane respiratory chain. on the membrane respiratory chain. 2ÿ
) in bacterial cells, which could be the main reason for the damage produced on the membrane respiratory chain.