Jones S, Yu B, Bainton N J, Birdsall M, Bycroft B W, Chhabra S R, Cox A J, Golby P, Reeves P J, Stephens S
Department of Biological Sciences, University of Warwick, Coventry, UK.
EMBO J. 1993 Jun;12(6):2477-82. doi: 10.1002/j.1460-2075.1993.tb05902.x.
Erwinia carotovora and Pseudomonas aeruginosa secrete exoenzymes that contribute to the pathogenesis of plant and mammalian infections respectively. E.carotovora mutants defective in synthesis of the pectinase, cellulase and protease exoenzymes were isolated and classified into two groups. Group 2 mutants were found to be defective in the production of a small freely diffusible molecule, N-3-(oxohexanoyl)-L-homoserine, lactone (HSL), and were avirulent. Addition of exogenous HSL to these group 2 mutants restores synthesis of the exoenzymes and virulence in planta. Of the exoenzymes of P.aeruginosa the metalloprotease, elastase, is an established virulence determinant. Mutants of P.aeruginosa that are defective in elastase production have been isolated and were again found to fall into two groups. Analogous to the group 2 mutants of E.carotovora, group 2 mutants of P. aeruginosa are defective in the synthesis of HSL and exogenous HSL restores elastase production. HSL has now been linked to the control of bioluminescence in Vibrio fischeri, carbapenem antibiotic production of E.carotovora and the above exoenzyme virulence determinants. This information significantly enhances our understanding of the extent and nature of pheromone mediated gene expression control in prokaryotes.
胡萝卜软腐欧文氏菌和铜绿假单胞菌分别分泌有助于植物和哺乳动物感染发病机制的胞外酶。分离出了在果胶酶、纤维素酶和蛋白酶胞外酶合成方面有缺陷的胡萝卜软腐欧文氏菌突变体，并将其分为两组。发现第2组突变体在一种小的可自由扩散分子N-3-(氧代己酰基)-L-高丝氨酸内酯（HSL）的产生上存在缺陷，并且无毒。向这些第2组突变体中添加外源HSL可恢复胞外酶的合成以及在植物中的毒力。在铜绿假单胞菌的胞外酶中，金属蛋白酶弹性蛋白酶是已确定的毒力决定因素。已经分离出了弹性蛋白酶产生有缺陷的铜绿假单胞菌突变体，并且再次发现它们分为两组。与胡萝卜软腐欧文氏菌的第2组突变体类似，铜绿假单胞菌的第2组突变体在HSL的合成上存在缺陷，外源HSL可恢复弹性蛋白酶的产生。现在已经将HSL与费氏弧菌中的生物发光控制、胡萝卜软腐欧文氏菌的碳青霉烯抗生素产生以及上述胞外酶毒力决定因素联系起来。这些信息显著增强了我们对原核生物中信息素介导的基因表达控制的程度和性质的理解。
