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假定Ppx1外聚酸酶对于Lacticaseibacillus paracasei中的多酸盐积累至关重要
Daniela Corrales1, Cristina Alcántara1, Manuel Zúñiga1
1Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Spain.
Applied and environmental microbiology
|April 15, 2024
概括
外聚酸酶Ppx1在Lactobacillus paracasei中对多酸盐 (多-P) 合成是意想不到的必不可少的,而不是降解. 这一发现揭示了Ppx1在细菌聚P积累中的新型调节作用,影响其生理功能.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 聚酸 (poly-P) 是一种对细菌生理学至关重要的线性聚合物,由聚酸激酶 (Ppk) 合成,并由外聚酸酶 (Ppx) 降解.
- 乳杆菌家族通常具有两个假定的外聚聚酸酶基因 (ppx1和ppx2) 与ppk基因聚集在一起,但它们的具体作用尚不清楚.
研究的目的:
- 为了研究两个假设的外聚酸酶基因,ppx1和ppx2,在Lacticaseibacillus paracasei中的多酸盐代谢中的特定功能.
- 阐明Ppx1在多酸盐合成中的作用及其与Ppk.的关系.
主要方法:
- 在L. paracasei BL23.23中构建和分析框架内删除突变 (Δppx1, Δppx2).
- 在野生型和突变菌株中分析聚聚聚的积累.
- 对ppk的基因表达分析.
- 通过在翻译中表达ppx1进行补充研究.
- 纯化的Ppx1和Ppx2.2的体外酶测定.
- 测试以确定Ppx1对Ppk活动的影响.
主要成果:
- 删除了ppx1,但没有删除ppx2,在L. paracasei中消除了聚P积累,尽管ppk表达没有改变.
- 在Δppx1菌株中,Poly-P合成只能通过表达ppx1在trans中恢复,而不是通过从等离子体中表达ppk.
- 纯化的Ppx2显示出外聚酸酶活性,而Ppx1缺乏可检测的催化活性,但在体外增强了Ppk活性.
结论:
- 在L. paracasei中,Ppx1对于聚P合成至关重要,与其在降解中的预期作用相反.
- Ppx1在聚P合成中起着意想不到的调节作用,可能通过调节Ppk活动,增加细菌聚P动态的复杂性.
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