Relaxed control of sugar utilization in Parageobacillus thermoglucosidasius DSM 2542.
Relaxed control of sugar utilization in Parageobacillus thermoglucosidasius DSM 2542.
复制标题
放宽对热葡萄糖副杆菌 DSM 2542 中糖利用的控制。
DOI：
10.1016/j.micres.2021.126957
复制
发表时间：
2022
影响因子：
6.7
通讯作者：
Liang J
中科院分区：
文献类型：
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作者：
Liang J
虽然碳分解代谢抑制(CCR)在一些更具特征的生物体中已经得到了深入的研究，但在嗜热菌中关于CCR的信息还很少。在这项工作中，研究了嗜热菌DSM 2542在葡萄糖存在下在戊糖上生长过程中的CCR。发酵条件下的生理研究表明，当DSM 2542在添加葡萄糖和木糖混合物的最低限度培养基中生长时，Ccr控制松散。通过qRT-PCR检测木糖异构酶的表达水平，也证实了这种非典型的CCR模式。幸运的是，编码邻苯二酚2，3-双加氧酶的pheB基因被发现在其3‘端与公认的分解代谢反应元件(Cre)高度相似，并被用来证实来自一个质粒的pheB的表达受到严格的CCR控制。生物信息学分析表明，Ccr对木糖代谢具有调控作用。DSM 2542可能主要通过控制戊糖转运子的表达而发生。对糖利用的放松控制可能反映了在这些操纵子中，CCPA-HPR(Ser46-P)或CCPA-CRH(Ser46-P)复合体对Cecre(S)的亲和力降低。
Though carbon catabolite repression (CCR) has been intensively studied in some more characterised organisms, there is a lack of information of CCR in thermophiles. In this work, CCR in the thermophile,Parageobacillus thermoglucosidasiusDSM 2542 has been studied during growth on pentose sugars in the presence of glucose. Physiological studies under fermentative conditions revealed a loosely controlled CCR when DSM 2542 was grown in minimal medium supplemented with a mixture of glucose and xylose. This atypical CCR pattern was also confirmed by studying xylose isomerase expression level by qRT-PCR. Fortuitously, thepheBgene, which encodes catechol 2, 3-dioxygenase was found to have acresite highly similar to the consensus catabolite-responsive element (cre) at its 3′ end and was used to confirm that expression ofpheBfrom a plasmid was under stringent CCR control. Bioinformatic analysis suggested that the CCR regulation of xylose metabolism inP. thermoglucosidasiusDSM 2542 might occur primarily via control of expression of pentose transporter operons. Relaxed control of sugar utilization might reflect a lower affinity of the CcpA-HPr (Ser46-P) or CcpA-Crh (Ser46-P) complexes to thecre(s) in these operons.