THE ICL1 GENE FROM SACCHAROMYCES-CEREVISIAE
THE ICL1 GENE FROM SACCHAROMYCES-CEREVISIAE
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DOI：
10.1111/j.1432-1033.1992.tb16720.x
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发表时间：
1992-03-15
期刊：
影响因子：
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通讯作者：
RODICIO, R
中科院分区：
文献类型：
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作者：
FERNANDEZ, E;MORENO, F;RODICIO, R
乙醛酸循环是酵母利用C2化合物的关键。在这个循环中，异柠檬酸裂解酶催化了其中一个关键反应。我们获得了缺乏可检测到的异柠檬酸裂解酶活性的突变体，筛选了它们不能在乙醇上生长。遗传和生化分析表明，他们携带了结构基因ICL1的缺陷。突变体用于分离该基因，该基因位于3.1 kb的BglII-SphI DNA片段上。然后，我们在单倍体酵母基因组中构建了一个缺失替代突变体。它没有任何异柠檬酸裂解酶活性，缺乏以乙醇为唯一碳源生长的能力。对携带该基因的DNA片段的两条链及其两侧区域进行了测序。检测到一个1671 bp的开放阅读框，编码一个557个氨基酸的蛋白，计算分子量为62515 Da。推导出的氨基酸序列与编码不同生物异柠檬酸裂解酶的基因有广泛的相似性。两个假定的camp依赖性蛋白激酶磷酸化位点可以解释该酶对碳分解代谢物失活的敏感性。
The glyoxylate cycle is essential for the utilization of C2 compounds by the yeast Saccharomyces cerevisiae. Within this cycle, isocitrate lyase catalyzes one of the key reactions. We obtained mutants lacking detectable isocitrate lyase activity, screening for their inability to grow on ethanol. Genetic and biochemical analysis suggested that they carried a defect in the structural gene, ICL1. The mutants were used for the isolation of this gene and it was located on a 3.1-kb BglII-SphI DNA fragment. We then constructed a deletion-substitution mutant in the haploid yeast genome. It did not have any isocitrate lyase activity and lacked the ability to grow on ethanol as the sole carbon source. Both strands of a DNA fragment carrying the gene and its flanking regions were sequenced. An open reading frame of 1671 bp was detected, encoding a protein of 557 amino acids with a calculated molecular mass of 62515 Da. The deduced amino acid sequence shows extensive similarities to genes encoding isocitrate lyases from various organisms. Two putative cAMP-dependent protein-kinase phosphorylation sites may explain the susceptibility of the enzyme to carbon catabolite inactivation.