PDF(Sci-hub)
Abstract：
The phosphoenolpyruvate (PEP): carbohydrate phosphotransferase system (PTS) allows bacteria to use various carbohydrates as energy resources including mannitol. The mannitol-specific PTS transporter in Vibrio cholerae is encoded by the mtlADR operon. Expression of the mtl operon has been shown to be strictly regulated by CRP, MtlS, and MtlR. In the present study, we investigated the regulation of mtlADR by the ferric uptake regulator (Fur). The results showed that Fur binds to the promoter-proximal DNA region of mtlADR to repress its transcription independent of iron, in mannitol-containing growth medium. The capacity for mannitol fermentation was significantly increased in Δfur relative to that of WT for normal and iron-replete growth media. The level of organic acids produced by Δfur was significantly enhanced relative to that produced by the WT strain in the normal and iron-replete media but not in an iron-starved medium. The results provided for a deeper understanding of the regulation of mtlADR in V. cholerae.
摘要：
磷酸烯醇丙酮酸（PEP）：碳水化合物磷酸转移酶系统（PTS）允许细菌使用各种碳水化合物作为能源，包括甘露醇。霍乱弧菌中甘露醇特异性PTS转运蛋白由mtlADR操纵子编码。已经证明mtl操纵子的表达受到CRP的严格调控，Mtls,和MtlR。在本研究中,我们研究了铁摄取调节剂（Fur）对mtlADR的调节。结果表明，Fur与mtlADR的启动子-近端DNA区域结合，以抑制其独立于铁的转录，在含甘露醇的生长培养基中。对于正常和铁充足的生长培养基，相对于WT，Δfur的甘露醇发酵能力显着增加。相对于WT菌株在正常和铁充足的培养基中产生的有机酸水平，Δfur产生的有机酸水平显着提高，但在铁缺乏的培养基中则没有。该结果为更深入地了解霍乱弧菌中mtlADR的调节提供了依据。
