glpFK操纵子编码的结构和调节甘油扩散的主持人和大肠杆菌甘油激酶k - 12。
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Weissenborn DL, Wittekindt N,拉尔森TJ
glpFK操纵子编码的结构和调节甘油扩散的主持人和大肠杆菌甘油激酶k - 12。
J生物化学杂志。1992年3月25日,267(9):6122 - 31所示。
- PubMed ID
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1372899 (在PubMed]
- 文摘
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glpFK操纵子地图附近分钟88连锁图上的大肠杆菌k - 12 glpF子近端。glpF基因编码一个细胞质膜蛋白促进甘油的扩散进入细胞。glpK基因编码甘油激酶。在目前的工作,核苷酸序列的5 '端操纵子,包括控制区域,glpF基因和glpK基因的一部分,是确定。主持人是预测含有281个氨基酸计算分子量为29780。它是一个高度疏水蛋白质用最少的六个潜在的跨膜α螺旋。glpFK操纵子的转录起始站点位于71个碱基对的上游提出了glpF翻译起始密码子。转录起始站点前序列类似于-10年和-35年的共识序列细菌的推动者。cAMP-cAMP受体蛋白的结合位点(CRP)复杂和glp阻遏了DNase我足迹。该地区的保护营地。CRP complex contained tandem sequences resembling the consensus sequence for CRP binding. The CRP sites were centered at 37.5 and 60.5 base pairs upstream of the start of transcription. The glp repressor protected an extensive area (-89 to -7 relative to the start point of transcription), sufficient for the binding of four repressor tetramers. Two additional binding sites for the repressor were identified within the glpK coding region. The DNA containing these two operators synergistically increased the apparent affinity of glp repressor for DNA fragments containing the four operators in the promoter region of the glpFK operon. With this study, a total of 13 operators for the glp regulon have been characterized. Comparison of these operators revealed the consensus 5'-WATGTTCGWT-3' for the operator half-site (W = A or T). The relative affinity of the glp repressor for the various glp operators was assessed in vivo using a promoter-probe vector. The relative apparent affinity of the control regions for glp repressor was glpFK greater than glpD greater than glpACB greater than glpTQ. The degree of catabolite repression for each of the operons was assessed using a similar system. In this case, the relative sensitivity of the glp operons to catabolite repression was glpTQ greater than glpFK greater than glpACB greater than glpD.