Kang Tae Sun, Korber Darren R, Tanaka Takuji
Department of Food and Bioproduct Sciences, College of Agriculture and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada.
Biotechnol Lett. 2014 Jun;36(6):1263-9. doi: 10.1007/s10529-014-1477-6. Epub 2014 Feb 22.
The regulatory role of a transcriptional regulator (PocR) in the 1,3-propanediol biosynthetic pathway of Lactobacillus panis PM1 contributes to the optimization of 1,3-propanediol production by this strain, which potentially will lead to 1,3-propanediol manufacturing efficiencies. Lactobacillus panis PM1 can utilize a 1,3-propanediol (1,3-PDO) biosynthetic pathway, consisting of diol dehydratase (PduCDE) and 1,3-PDO dehydrogenase, as a NADH recycling system, to survive under various environmental conditions. In this study, we identified a key transcriptional repressor (PocR) which was annotated as a transcriptional factor of AraC family as part of the 1,3-PDO biosynthetic pathway of L. panis PM1. The over-expression of the PocR gene resulted in the significant repression (81 %) of pduC (PduCDE large subunit) transcription, and subsequently, the decreased activity of PduCDE by 22 %. As a result of the regulation of PduCDE, production of both 3-hydroxypropionaldehyde and 1,3-PDO in the PocR over-expressing strain were significantly decreased by 40 % relative to the control strain. These results clearly demonstrate the transcriptional repressor role of PocR in the 1,3-PDO biosynthetic pathway.
转录调节因子（PocR）在嗜麦芽窄食单胞菌PM1的1,3-丙二醇生物合成途径中的调节作用有助于优化该菌株的1,3-丙二醇产量，这可能会提高1,3-丙二醇的生产效率。嗜麦芽窄食单胞菌PM1可以利用由二醇脱水酶（PduCDE）和1,3-丙二醇脱氢酶组成的1,3-丙二醇（1,3-PDO）生物合成途径作为NADH循环系统，在各种环境条件下生存。在本研究中，我们鉴定了一个关键的转录抑制因子（PocR），它被注释为AraC家族的转录因子，是嗜麦芽窄食单胞菌PM1的1,3-PDO生物合成途径的一部分。PocR基因的过表达导致pduC（PduCDE大亚基）转录显著抑制（81%），随后，PduCDE的活性降低了22%。由于PduCDE的调节，与对照菌株相比，PocR过表达菌株中3-羟基丙醛和1,3-PDO的产量均显著降低了40%。这些结果清楚地证明了PocR在1,3-PDO生物合成途径中的转录抑制作用。
