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Cloning and characterization of the lactate‐specific inducible gene KlCYB2 , encoding the cytochrome b 2 of Kluyveromyces lactis
Author(s) -
Alberti Adriana,
Goffrini Paola,
Ferrero Iliana,
Lodi Tiziana
Publication year - 2000
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/(sici)1097-0061(200005)16:7<657::aid-yea560>3.0.co;2-#
Subject(s) - kluyveromyces lactis , biology , kluyveromyces , biochemistry , gene , mutant , homology (biology) , genbank , yeast , saccharomyces cerevisiae , molecular cloning , schizosaccharomyces pombe , microbiology and biotechnology , peptide sequence
In yeast the utilization of lactate requires two enzymes, the D and L ‐lactate ferricytochrome c oxidoreductase ( D and L ‐LCR), which stereospecifically oxidize D ‐ and L ‐lactate to pyruvate. These enzymes are nuclearly encoded and localized in mitochondria. In the yeast Kluyveromyces lactis , a mutant devoid of D ‐ and L ‐LCR activities and unable to grow on racemic lactate was isolated. Transformation of the mutant with a K. lactis genomic library allowed the isolation of the KlCYB2 gene, restoring the growth on lactate and the L ‐LCR activity. The KlCYB2 gene and its flanking regions were sequenced (Accession No. AJ243324; EMBL/GenBank databases). The deduced amino acid sequence is highly homologous to the corresponding Saccharomyces cerevisiae and Hansenula anomala protein sequences previously characterized. The homology is missed in the N ‐terminal region, corresponding to the presequence cleaved during import into mitochondria. Analysis of KlCYB2 gene expression indicated that, in contrast to S. cerevisiae , the major regulatory feature is induction by lactate. Copyright © 2000 John Wiley & Sons, Ltd.