Carbon Catabolite Regulation in Bacillus subtilis

枯草芽孢杆菌中碳分解代谢物的调节

• 批准号: 9723091
• 负责人: Tina Henkin
• 金额: $ 36万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9723091&HistoricalAwards=false
• 关键词: Carbon; Catabolite; Regulation; Bacillus; subtilis

Henkin 9723091 The mechanisms for carbon catabolite regulation in Gram-positive bacteria such as Bacillus subtilis are not well-understood, but are known to differ from the systems found in Escherichia coli and its relatives. During growth in high levels of a readily utilized carbon source such as glucose, expression of genes encoding enzymes for utilization of secondary carbon sources is repressed by CcpA, a DNA binding protein which recognizes conserved operator sites in the promoter regions of target genes. Under these conditions. CcpA also activates transcription of the ackA gene, which is involved in excretion of excess carbon in the form of acetate. Activation involves binding of CcpA protein to a sequence identical to the operator sites for repression: for ackA, the target. site for CcpA-dependent activation is located upstream of the promoter. The molecular mechanism for transcriptional activation of ackA by CcpA is unknown, and elucidation of this mechanism is a major goal of this project. These studies will involve investigation of cis-acting sequences required for activation, DNA binding studies, and analysis of the effect of RNA polymerase mutations. The second major goal of this project is the identification of additional genes subject to transcriptional activation by CcpA. Characterization of new target genes will provide information about the global role of CcpA as a regulator of carbon metabolism in B. subtilis, and will also provide insight into the mechanism of transcriptional activation through analysis of conserved features. The third major goal of this project is the analysis of the mechanism for the response of CcpA activity to carbon source activity. This project will provide new information about molecular mechanisms for metabolic control in microorganisms, and mechanisms for transcriptional activation. Homologs of the B. subtilis carbon catabolite regulatory protein CcpA have been identified in a variety of Gram-positive organisms, indicating that the information o btained here is likely to apply to a number of experimental systems less directly amenable to genetic analysis. A greater understanding of carbon metabolism and regulation will also improve the utility of Bacillus systems for industrial production.

在革兰氏阳性细菌如枯草芽孢杆菌中碳分解代谢物调节的机制还不清楚，但已知与大肠杆菌及其亲属中发现的系统不同。在高水平的容易利用的碳源如葡萄糖中生长期间，编码用于利用次级碳源的酶的基因的表达被CcpA抑制，CcpA是一种DNA结合蛋白，其识别靶基因的启动子区中的保守操纵子位点。在这种情况下。CcpA还激活ackA基因的转录，该基因参与以乙酸盐的形式排泄过量的碳。激活涉及CcpA蛋白结合到与阻遏的操纵子位点相同的序列上：对于ackA，靶点。CcpA依赖性激活的位点位于启动子的上游。CcpA转录激活ackA的分子机制尚不清楚，阐明这一机制是本项目的主要目标。这些研究将涉及激活所需的顺式作用序列的研究、DNA结合研究和RNA聚合酶突变效应的分析。该项目的第二个主要目标是识别受CcpA转录激活的其他基因。新靶基因的鉴定将提供关于CcpA作为B中碳代谢调节剂的全球作用的信息。枯草芽孢杆菌，也将提供深入了解转录激活的机制，通过分析保守的功能。 本项目的第三个主要目标是分析CcpA活性对碳源活性的响应机制。 该项目将提供有关微生物代谢控制的分子机制和转录激活机制的新信息。B的同系物。枯草杆菌碳代谢产物调节蛋白CcpA已在多种革兰氏阳性菌中鉴定，表明此处获得的信息可能适用于许多不太直接适合遗传分析的实验系统。对碳代谢和调节的更深入了解也将提高芽孢杆菌系统在工业生产中的效用。