College of Agriculture, Guangxi University, Nanning, 530004, China.
College of Plant Protection, China Agricultural University, Beijing, 100193, China.
BMC Microbiol. 2020 Feb 24;20(1):39. doi: 10.1186/s12866-020-1714-1.
The polyketide antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG), produced by Pseudomonas fluorescens 2P24, is positively regulated by the GacS-GacA two-component system.
Here we reported on the characterization of DsbA1 (disulfide oxidoreductase) as novel regulator of biocontrol activity in P. fluorescens. Our data showed that mutation of dsbA1 caused the accumulation of 2,4-DAPG in a GacA-independent manner. Further analysis indicated that DsbA1 interacts with membrane-bound glucose dehydrogenase Gcd, which positively regulates the production of 2,4-DAPG. Mutation of cysteine (C)-235, C275, and C578 of Gcd, significantly reduced the interaction with DsbA1, enhanced the activity of Gcd and increased 2,4-DAPG production.
Our results suggest that DsbA1 regulates the 2,4-DAPG concentration via fine-tuning the function of Gcd in P. fluorescens 2P24.
多酮类抗生素 2,4-二乙酰基间苯三酚（2,4-DAPG）由荧光假单胞菌 2P24 产生，受 GacS-GacA 双组分系统的正向调控。
本研究报道了 DsbA1（二硫键氧化还原酶）作为荧光假单胞菌生物防治活性的新型调控因子的特征。我们的数据表明，dsbA1 的突变以 GacA 非依赖性方式导致 2,4-DAPG 的积累。进一步的分析表明，DsbA1 与膜结合型葡萄糖脱氢酶 Gcd 相互作用，后者正向调节 2,4-DAPG 的产生。Gcd 的半胱氨酸（C）-235、C275 和 C578 的突变，显著降低了与 DsbA1 的相互作用，增强了 Gcd 的活性并增加了 2,4-DAPG 的产生。
我们的结果表明，DsbA1 通过精细调节 P. fluorescens 2P24 中 Gcd 的功能来调节 2,4-DAPG 浓度。
