Regulation of production of the antifungal metabolite 2,4-diacetylphloroglucinol in Pseudomonas fluorescens F113:: genetic analysis of phlF as a transcriptional repressor
Regulation of production of the antifungal metabolite 2,4-diacetylphloroglucinol in Pseudomonas fluorescens F113:: genetic analysis of phlF as a transcriptional repressor
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DOI：
10.1099/00221287-146-2-537
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发表时间：
2000-02-01
期刊：
影响因子：
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通讯作者：
O'Gara, F
中科院分区：
文献类型：
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作者：
Delany, I;Sheehan, MM;O'Gara, F
抗真菌代谢物 2,4-二乙酰基间苯三酚在荧光假单胞菌的生物防治能力中发挥着重要作用。荧光假单胞菌 F113 的间苯三酚生物合成基因座先前已被分离，根据核苷酸序列数据，在上游鉴定了推定的调节基因（phlF），该基因与 phlACBD 间苯三酚生物合成基因不同地转录。 PhlF 与 EMBL 数据库中的各种转录抑制子相似，并且在其氨基酸序列中呈现螺旋-转角-螺旋基序。将phlF克隆到表达载体中并纯化PhlF蛋白产物。凝胶阻滞实验证明 PhlF 是一种 DNA 结合蛋白，并表明它与 phlA-phlF 基因间区域结合。将多拷贝的phlF引入荧光假单胞菌F113中导致该菌株中间苯三酚生产的抑制。该效应是在转录水平上介导的，因为在此背景下间苯三酚生物合成基因融合体的表达同样受到抑制。此外，phlF的失活导致该菌株中间苯三酚生产的去抑制。
The antifungal metabolite 2,4-diacetylphloroglucinol plays a major role in the biocontrol capabilities of Pseudomonas fluorescens. The phloroglucinol biosynthetic locus of P. fluorescens F113 has been isolated previously, From nucleotide sequence data, a putative regulator gene (phlF) was identified upstream and divergently transcribed from the phlACBD phloroglucinol biosynthetic genes. PhlF shows similarity to various transcriptional repressors in the EMBL database and exhibits a helix-turn-helix motif in its amino acid sequence. phlF was cloned into an expression vector and the PhlF protein product was purified. Gel retardation experiments demonstrated PhlF to be a DNA-binding protein and showed that it binds to the phlA-phlF intergenic region. Introduction of phlF into P. fluorescens F113 in multiple copies resulted in repression of phloroglucinol production in this strain, This effect was mediated at the transcription level since the expression of a phloroglucinol biosynthetic gene fusion in this background was equally repressed, Furthermore, the inactivation of phlF results in derepression of phloroglucinol production in this strain.