Global regulatory circuits together with more specific local regulators play a notable role when cells are adapting to environmental changes. Lactococcus lactis is a lactic acid bacterium abundant in nature fermenting most mono- and disaccharides. Comparative genomics analysis of the operons encoding the proteins and enzymes crucial for catabolism of lactose, maltose and threhalose revealed an obvious unity in operon organisation . The local regulator of each operon was located in a divergent transcriptional direction to the rest of the operon including the transport protein-encoding genes. Furthermore, in all three operons a catabolite responsive element (CRE) site was detected inbetween the gene encoding the local regulator and one of the genes encoding a sugar transport protein. It is evident that regardless of type of transport system and catabolic enzymes acting upon lactose, maltose and trehalose, respectively, Lc. lactis shows unity in both operon organisation and regulation of these catabolic operons. This knowledge was further extended to other catabolic operons in Lc. lactis and the two related bacteria Lactobacillus plantarum and Listeria monocytogenes. Thirty-nine catabolic operons responsible for degradation of sugars and sugar alcohols in Lc. lactis, Lb. plantarum and L. monocytogenes were investigated and the majority of those possessed the same organisation as the lactose, maltose and trehalose operons of Lc. lactis. Though, the frequency of CRE sites and their location varied among the bacteria. Both Lc. lactis and Lb. plantarum showed CRE sites in direct proximity to genes coding for proteins responsible for sugar uptake. However, in L. monocytogenes CRE sites were not frequently found and not in the vicinity of genes encoding transport proteins, suggesting a more local mode of regulation of the catabolic operons found and/or the use of inducer control in this bacterium.

中文翻译：

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植物乳杆菌，乳酸乳球菌和单核细胞增生李斯特菌中分解代谢操纵子的组织和调节的统一性。

当电池适应环境变化时，全球监管电路与更具体的本地监管机构一起发挥着显著作用。乳酸乳球菌是自然界中发酵大多数单糖和双糖丰富的乳酸菌。操纵子编码对乳糖，麦芽糖和海藻糖分解代谢至关重要的蛋白质和酶的操纵子的比较基因组学分析表明，操纵子组织具有明显的统一性。每个操纵子的局部调节子位于与其他操纵子（包括转运蛋白编码基因）不同的转录方向上。此外，在所有三个操纵子中，在编码局部调节子的基因与编码糖转运蛋白的基因之一之间检测到分解代谢物响应元件（CRE）位点。显然，无论运输系统的类型如何，分解代谢酶分别作用于乳糖，麦芽糖和海藻糖Lc。乳酸菌在操纵子的组织和对这些分解代谢操纵子的调节上均表现出统一性。该知识进一步扩展到了Lc中的其他分解代谢操纵子。乳酸和两种相关细菌植物乳杆菌和单核细胞增生李斯特菌。39个分解代谢操纵子负责Lc中糖和糖醇的降解。乳酸，磅。调查了植物乳杆菌和单核细胞增生李斯特菌，其中大多数具有与Lc的乳糖，麦芽糖和海藻糖操纵子相同的组织。乳酸菌。虽然如此，CRE位点的频率及其位置在细菌之间有所不同。既LC。乳酸和Lb。车前草显示CRE位点与编码负责糖摄取的蛋白质的基因直接相邻。然而，在单核细胞增生李斯特氏菌中，很少发现CRE位点，也不在编码转运蛋白的基因附近，这表明发现了分解代谢操纵子的更局部调节模式和/或在该细菌中使用了诱导物控制。