Mechanism of Action of Pseudomonas syringae Phytotoxin, Syringomycin

摘要: Syringomycin, a peptide toxin produced by the phytopathogen Pseudomonas syringae pv preferentially stimulated (2-fold) vanadate-sensitive ATPase activity associated with plasma membrane of red beet storage tissue. The had very slight effect on tonoplast and no detectable mitochondrial ATPase. Optimal stimulation was achieved 10 to 50 micrograms syringomycin per 25 protein. Treatment membranes 0.1% (weight/volume) deoxycholate eliminated activation effect, enzyme solubilized Zwittergent 3-14 not affected syringomycin. activated same extent at KCl concentrations ranging from 0 millimolar. Valinomycin, nigericin, carbonylcyanide p-trifluoromethoxyphenylhydrazone, gramicidin did increase activity. However, these ionophores hinder ability stimulate We suggest that does altering ion gradients nor directly interacting enzyme, but possibly through regulatory effectors or covalent modification enzyme.