The CIT3 gene of Saccharomyces cerevisiae encodes a second mitochondrial isoform of citrate synthase.
We have identified a third citrate synthase gene in Saccharomyces cerevisiae which we have called CIT3. Complementation of a citrate synthase-deficient strain of Escherichia coli by lacZ::CIT3 gene fusions demonstrated that the CIT3 gene encodes an active citrate synthase. The CIT3 gene seems to be regulated in the same way as CIT1, which encodes the mitochondrial isoform of citrate synthase. Deletion of the CIT3 gene in a delta cit1 background severely reduced growth on the respiratory substrate glycerol, whilst multiple copies of the CIT3 gene in a delta cit1 background significantly improved growth on acetate. In vitro import experiments showed that cit3p is transported into the mitochondria. Taken together, these data show that the CIT3 gene encodes a second mitochondrial isoform of citrate synthase.
Jia
Y K
YK
Centre de Génétique Moléculaire, Laboratoire propre du CNRS associé à l'Université Pierre et Marie Curie, Gif-sur-Yvette, France.
Bécam
A M
AM
Herbert
C J
CJ
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002950:Citrate (si)-Synthase / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015870:Gene Expression; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D007763:Lac Operon; D008928:Mitochondria / Q000201:enzymology; D008969:Molecular Sequence Data; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D005656:Fungal Proteins; D007527:Isoenzymes; D011993:Recombinant Fusion Proteins; D002950:Citrate (si)-Synthase