glc locus of Escherichia coli: Characterization of genes encoding the subunits of glycolate oxidase and the glc regulator protein
glc locus of Escherichia coli: Characterization of genes encoding the subunits of glycolate oxidase and the glc regulator protein
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DOI：
10.1128/jb.178.7.2051-2059.1996
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发表时间：
1996-04-01
影响因子：
3.2
通讯作者：
Baldoma, L
中科院分区：
文献类型：
--
作者：
Pellicer, MT;Badia, J;Baldoma, L
已知与大肠杆菌中乙醇酸利用性状相关的基因座glc（min 64.5）含有编码苹果酸合酶G的glcB和乙醇酸氧化酶活性所需的基因。亚克隆、测序、插入突变和表达研究显示了另外5个基因：glcC和另一方向的glcD、glcE、glcF和glcC，然后是glcB。基因glcC可以编码glc调节蛋白。因此，氯霉素乙酰转移酶插入突变消除了乙醇酸氧化酶和苹果酸合酶G的活性。glcD和glcE编码的蛋白质与几种黄素酶相似，glcF编码的蛋白质与铁硫蛋白相似，glcG编码的蛋白质与任何一组蛋白质都没有明显的相似性。插入突变的氯霉素乙酰转移酶盒中的任一glcD，glcE，或glcF废除乙醇酸氧化酶的活性，表明推测这些蛋白质是这种酶的亚基。glcC插入突变对乙醇酸代谢没有影响。北方（RNA）印迹实验显示glcC的组成型表达，但诱导表达的结构基因，并提供了一个单一的多顺反子转录没有证据。
The locus glc (min 64.5), associated with the glycolate utilization trait in Escherichia coli, is known to contain glcB, encoding malate synthase G, and the gene(s) needed for glycolate oxidase activity. Subcloning, sequencing, insertion mutagenesis, and expression studies showed five additional genes: glcC and in the other direction glcD, glcE, glcF, and glcC followed by glcB. The gene glcC may encode the glc regulator protein. Consistently a chloramphenicol acetyltransferase insertion mutation abolished both glycolate oxidase and malate synthase G activities. The proteins encoded from glcD and glcE displayed similarity to several flavoenzymes, the one from glcF was found to be similar to iron-sulfur proteins, and that from glcG had no significant similarity to any group of proteins. The insertional mutation by a chloramphenicol acetyltransferase cassette in either glcD, glcE, or glcF abolished glycolate oxidase activity, indicating that presumably these proteins are subunits of this enzyme. No effect on glycolate metabolism was detected by insertional mutation in glcC. Northern (RNA) blot experiments showed constitutive expression of glcC but induced expression for the structural genes and provided no evidence for a single polycistronic transcript.