The DNA gyrase inhibitors, nalidixic acid and oxolinic acid, prevent iron-mediated repression of catechol siderophore synthesis in Azotobacter vinelandii.
The DNA gyrase inhibitors, nalidixic acid and oxolinic acid, prevent iron-mediated repression of catechol siderophore synthesis in Azotobacter vinelandii.
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DOI：
10.1007/bf01128018
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发表时间：
1988-01-01
期刊：
影响因子：
--
通讯作者：
Patrick, J
中科院分区：
文献类型：
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作者：
Page, W J;Patrick, J
低浓度的萘啶酸和oxolinic酸，只是抑制固氮菌vinelandii的生长促进生产的儿茶酚铁载体azotochelin和aminochelin，在正常抑制浓度的Fe 3+的存在下。存在对绿脓菌荧光素铁载体、固氮菌肌动蛋白的有限影响，其中低浓度的Fe 3+被赋予较少的阻遏，但是由较高浓度的Fe 3+引起的阻遏是正常的。这些药物没有诱导高分子量的铁抑制性外膜蛋白和儿茶酚铁载体合成的调节类似的影响，没有产生新生霉素，香豆霉素，溴化乙锭。萘啶酸和Fe3+添加到铁限制细胞的时机是至关重要的。萘啶酸必须加入前儿茶酚铁载体合成的铁抑制和铁充足的增长开始之前。然而，儿茶酚铁载体的持续产生并不是因为干扰了正常的铁吸收。这些数据表明，萘二甲酸防止正常的铁阻遏儿茶酚铁载体的合成，但不能逆转铁阻遏一旦发生。本文还讨论了DNA促旋酶活性在儿茶酚铁载体合成调控中的可能作用。
Low concentrations of nalidixic acid and oxolinic acid that were just inhibitory to Azotobacter vinelandii growth promoted the production of the catechol siderophores azotochelin and aminochelin, in the presence of normally repressive concentrations of Fe3+. There was a limited effect on the pyoverdin siderophore, azotobactin, where low concentrations of Fe3+ were rendered less repressive, but the repression by higher concentrations of Fe3+ was normal. These drugs did not induce high-molecular-mass iron-repressible outer-membrane proteins and similar effects on the regulation of catechol siderophore synthesis were not produced by novobiocin, coumermycin, or ethidium bromide. The timing of nalidixic acid and Fe3+ addition to iron-limited cells was critical. Nalidixic acid had to be added before iron-repression of catechol siderophore synthesis and before the onset of iron-sufficient growth. Continued production of the catechol siderophores, however, was not due to interference with normal iron uptake. These data indicated that nalidixic acid prevented normal iron-repression of catechol siderophore synthesis but could not reverse iron repression once it had occurred. The possible roles of DNA gyrase activity in the regulation of catechol siderophore synthesis is discussed.