Crossregulation of rapamycin and elaiophylin biosynthesis by RapH in Streptomyces rapamycinicus
Crossregulation of rapamycin and elaiophylin biosynthesis by RapH in Streptomyces rapamycinicus
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DOI：
10.1007/s00253-022-11847-9
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发表时间：
2022-02-26
影响因子：
5
通讯作者：
Lu, Yinhua
中科院分区：
文献类型：
--
作者：
He, Wenyan;Wang, Wenfang;Lu, Yinhua
雷帕霉素是由雷帕霉素链霉菌产生的一种重要的大环抗生素。在雷帕霉素生物合成基因簇（BGC）中，有多达五个调控基因，它们在雷帕霉素生物合成的调控中发挥着重要作用。在这里，我们证明了雷帕霉素位于BGC的LAL家族调节因子RapH协同调节雷帕霉素和榄叶素的生物合成。我们发现rapH过表达不仅导致雷帕霉素产量增加，而且还导致另一种I型聚酮抗生素elaiophylin的合成增加。与此一致，rapH缺失导致两种抗生素的产量减少。通过实时荧光定量RT-PCR结合β-葡萄糖醛酸酶报告基因分析，确定了4个受RapH调控的靶基因，包括雷帕霉素BGC中的rapL（编码赖氨酸环脱氨酶）/rapH和ela 3（编码LuxR家族调节因子）/ela 9（编码一种假想蛋白）。其中一个被RapH识别的相对保守的标签序列为5 '-GTT/AC-N-8-GTAC-3'，它由两个4-nt的反向重复序列组成，中间间隔8-nt。综上所述，我们的研究结果表明，RapH参与协调调节两个不同的BGC指定两个无关的抗生素，雷帕霉素和elaiophylin。这些结果进一步扩展了我们对S. RapH是一个簇定位的调控因子，控制着两种抗生素的合成，鉴定了4个RapH识别的启动子区域，并确定了一个16-nt的RapH调控所必需的DNA标签序列。
Rapamycin is an important macrocyclic antibiotic produced by Streptomyces rapamycinicus. In the rapamycin biosynthetic gene cluster (BGC), there are up to five regulatory genes, which have been shown to play important roles in the regulation of rapamycin biosynthesis. Here, we demonstrated that the rapamycin BGC-situated LAL family regulator RapH co-ordinately regulated the biosynthesis of both rapamycin and elaiophylin. We showed that rapH overexpression not only resulted in enhanced rapamycin production but also led to increased synthesis of another type I polyketide antibiotic, elaiophylin. Consistent with this, rapH deletion resulted in decreased production of both antibiotics. Through real-time RT-PCR combined with beta-glucuronidase reporter assays, four target genes controlled by RapH, including rapL (encoding a lysine cyclodeaminase)/rapH in the rapamycin BGC and ela3 (encoding a LuxR family regulator)/ela9 (encoding a hypothetical protein) in the elaiophylin BGC, were identified. A relatively conserved signature sequence recognized by RapH, which comprises two 4-nt inverted repeats separated by 8-nt, 5'-GTT/AC-N-8-GTAC-3', was defined. Taken together, our findings demonstrated that RapH was involved in co-ordinated regulation of two disparate BGCs specifying two unrelated antibiotics, rapamycin and elaiophylin. These results further expand our knowledge of the regulation of antibiotic biosynthesis in S. rapamycinicus.Key pointsThe cluster-situated regulator RapH controlled the synthesis of two antibiotics.Four promoter regions recognized by RapH were identified.A 16-nt signature DNA sequence essential for RapH regulation was defined.