Posgrado en Ciencias Biológicas, Instituto de Investigaciones Biomédicas, Universidad Nacional Autonoma de México, Mexico.
Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico.
Microbiology (Reading). 2021 Mar;167(3). doi: 10.1099/mic.0.001037. Epub 2021 Feb 23.
can use C4-dicarboxylic acids to grow heterotrophically or photoheterotropically, and it was previously demonstrated in that the DctPQM transporter system is essential to support growth using these organic acids under heterotrophic but not under photoheterotrophic conditions. In this work we show that in this transporter system is essential for photoheterotrophic and heterotrophic growth, when C4-dicarboxylic acids are used as a carbon source. We also found that over-expression of is detrimental for photoheterotrophic growth in the presence of succinic acid in the culture medium. In agreement with this, we observed a reduction of the promoter activity in cells growing under these conditions, indicating that the amount of DctPQM needs to be reduced under photoheterotrophic growth. It has been reported that the two-component system DctS and DctR activates the expression of . Our results demonstrate that in the absence of DctR, is still expressed albeit at a low level. In this work, we have found that the periplasmic component of the transporter system, DctP, has a role in both transport and in signalling the DctS/DctR two-component system.
可以利用 C4-二羧酸进行异养或光异养生长，先前的研究表明，DctPQM 转运系统对于利用这些有机酸进行异养生长是必不可少的，但对于光异养生长则不是。在这项工作中，我们表明，在 中，当 C4-二羧酸作为碳源时，该转运系统对于光异养和异养生长都是必不可少的。我们还发现，在培养基中存在琥珀酸的情况下，过度表达 对光异养生长是有害的。与此一致，我们观察到在这些条件下生长的细胞中 启动子活性降低，表明在光异养生长下需要减少 DctPQM 的数量。据报道，双组分系统 DctS 和 DctR 激活 的表达。我们的结果表明，在缺乏 DctR 的情况下， 仍被表达，尽管表达水平较低。在这项工作中，我们发现转运系统的周质成分 DctP 在运输和信号转导 DctS/DctR 双组分系统方面都发挥作用。
