Transcription Analysis of a Lantibiotic Gene Cluster from Bifidobacterium longum DJO10A
Transcription Analysis of a Lantibiotic Gene Cluster from Bifidobacterium longum DJO10A
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DOI：
10.1128/aem.00571-11
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发表时间：
2011-09-01
影响因子：
4.4
通讯作者：
O'Sullivan, Daniel J.
中科院分区：
文献类型：
--
作者：
Lee, Ju-Hoon;Li, Xiulan;O'Sullivan, Daniel J.
长双歧杆菌DJO 10A先前被证明产生硫醚抗生素，但仅在琼脂培养基上生长期间。为了评价在肉汤培养基中生产这种羊毛硫抗生素的可行性，进行了拉娜A基因的转录分析。B的肉汤和琼脂培养物的比较微阵列分析。longum DJO 10A揭示了lantibiotic的生产、修饰、转运/肽酶和免疫基因在琼脂培养中显著上调，而双组分调节基因在两种条件下同等表达。这表明信号转导调节系统应该在肉汤培养物中起作用。实时PCR和北方杂交证实，拉娜基因的表达显着抑制肉汤培养。从琼脂生长的培养物中获得粗lantibiotic制剂，并且其抗菌谱分析揭示了宽的抑制范围。将该浸提液加入B的肉汤培养物中。longum DJO 10 A以剂量依赖性方式诱导拉娜基因表达。使用>10%的诱导肉汤培养物的亚接种维持拉娜表达。拉娜的表达具有对数期特异性，在稳定期显著下调。拉娜的转录起始分析揭示了一个284-bp的5'非翻译区，这被认为参与了转录的抑制，而位于相对于转录起始的bp-75处的反向重复结构被策略性地定位，可能作为双组分反应调节剂的结合位点起作用。了解该拉娜基因的转录调控是在肉汤培养基中生产这种新型且潜在有趣的lantibiotic的第一步。
Bifidobacterium longum DJO10A was previously demonstrated to produce a lantibiotic, but only during growth on agar media. To evaluate the feasibility of production of this lantibiotic in broth media, a transcription analysis of the lanA gene was undertaken. Comparative microarray analysis of broth and agar cultures of B. longum DJO10A revealed that the lantibiotic production, modification, transport/peptidase, and immunity genes were significantly upregulated in agar cultures, while the two-component regulatory genes were expressed equally under both conditions. This suggested that the signal transduction regulatory system should function in broth cultures. Real-time PCR and Northern hybridization confirmed that lanA gene expression was significantly repressed in broth cultures. A crude lantibiotic preparation from an agar-grown culture was obtained, and its antimicrobial spectrum analysis revealed a broad inhibition range. Addition of this extract to broth cultures of B. longum DJO10A induced lanA gene expression in a dose-dependent fashion. Subinoculation using >10% of an induced broth culture maintained lanA expression. The expression of lanA was log-phase specific, being significantly downregulated in stationary phase. Transcription start analysis of lanA revealed a 284-bp 5' untranslated region, which was proposed to be involved in repression of transcription, while an inverted repeat structure located at bp -75 relative to the transcription start was strategically located to likely function as a binding site for the two-component response regulator. Understanding the transcription regulation of this lanA gene is the first step toward enabling production of this novel and potentially interesting lantibiotic in broth cultures.