The ICL1 Gene From Saccharomyces Cerevisiae

Eur J Biochem. 1992 Mar 15;204(3):983-90. doi: 10.1111/j.1432-1033.1992.tb16720.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Blotting, Western
  • Chromosome Deletion
  • Cloning, Molecular
  • DNA, Fungal / genetics
  • Ethanol / metabolism
  • Genes, Fungal / genetics
  • Isocitrate Lyase / genetics*
  • Molecular Sequence Data
  • Nucleic Acid Hybridization
  • Open Reading Frames
  • Phosphorylation
  • Plasmids
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics
  • Sequence Homology, Nucleic Acid


  • DNA, Fungal
  • Ethanol
  • Isocitrate Lyase

Associated data

  • GENBANK/S87178
  • GENBANK/S87180
  • GENBANK/S87218
  • GENBANK/S87221
  • GENBANK/S87223
  • GENBANK/X61271
  • GENBANK/X65178
  • GENBANK/X65179
  • GENBANK/X65180
  • GENBANK/X65181