Open AccessThe ICL 1 gene from Saccharomyces cerevisiae
Author(s) -
FERNÁNDEZ Ernestina,
MORENO Fernando,
RODICIO Rosaura
Publication year - 1992
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1992.tb16720.x
Subject(s) - isocitrate lyase , saccharomyces cerevisiae , glyoxylate cycle , biology , gene , biochemistry , mutant , open reading frame , yeast , genetics , microbiology and biotechnology , peptide sequence , enzyme
The glyoxylate cycle is essential for the utilization of C 2 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, ICL 1. The mutants were used for the isolation of this gene and it was located on a 3.1‐kb Bg /II‐ Sph I 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.