The pleiotropic regulator AdpA-L directly controls the pathway-specific activator of nikkomycin biosynthesis in Streptomyces ansochromogenes
The pleiotropic regulator AdpA-L directly controls the pathway-specific activator of nikkomycin biosynthesis in Streptomyces ansochromogenes
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DOI：
10.1111/j.1365-2958.2009.06681.x
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发表时间：
2009-05-01
影响因子：
3.6
通讯作者：
Tan, Huarong
中科院分区：
文献类型：
--
作者：
Pan, Yuanyuan;Liu, Gang;Tan, Huarong
产nikkomycin的Streptomyces ansochromogenes具有链霉菌关键的多效性调控基因adpA的同源物（adpA- l）。基因破坏和基因互补表明adpA-L是尼克霉素生物合成和形态分化所必需的。转录分析表明，尼克霉素生物合成特异性激活基因sanG的转录依赖于AdpA-L。在凝胶转移和DNA酶1足迹分析中，纯化的his6标记的重组AdpA-L蛋白在五个位点上结合了sanG的上游区域，这些位点分布在超过1000个碱基的DNA上，其中大部分位于转录区域内。在这些结合位点上发现了一致的adpa - l结合序列，5'-TGGCNNVWHN-3' （V: C、A或G； W: A或T； H: A、T或C； N：任意核苷酸）。对携带突变AdpA-L结合位点的sanG的转录分析表明，位点I突变时sanG的转录被消除，位点V突变时sanG的转录减少，而结合位点II、III和IV突变时sanG的转录增加。同时，与野生型相比，突变位点III的nikkomycin产量增加。这项工作突出了尼克霉素生物合成调控的复杂性的新水平。
The nikkomycin-producing strain Streptomyces ansochromogenes has a homologue (adpA-L) of the key pleiotropic Streptomyces regulatory gene adpA. Gene disruption and genetic complementation revealed that adpA-L was required for both nikkomycin biosynthesis and morphological differentiation. Transcriptional analysis suggested that the transcription of sanG, the specific activator gene for nikkomycin biosynthesis, was dependent on AdpA-L. In gel-shift and DNase 1 footprinting assays, the purified His6-tagged recombinant AdpA-L protein bound the upstream region of sanG at five sites, which are spread over more than one kilobase of DNA and most of which is inside the transcribed region. A consensus AdpA-L-binding sequence, 5'-TGGCNNVWHN-3' (V: C, A or G; W: A or T; H: A, T or C; N: any nucleotide) was found in these binding sites. Transcriptional analysis of sanG carrying mutated AdpA-L binding sites showed that transcription of sanG was eliminated when site I was mutated and its trascription was decreased when site V was mutated, whereas it was increased when the binding sites II, III or IV were mutated. Meanwhile, nikkomycin production of the mutated site III strain was enhanced comparing with the wild-type strain as control. This work highlights a new level of complexity in the regulation of nikkomycin biosynthesis.