Inducible overexpression of the FUM1 gene in saccharomyces cerevisiae: Localization of fumarase and efficient fumaric acid bioconversion to L-Malic acid

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Applied and Environmental Microbiology; (USA)

OSTI ID:6273188

Peleg, Y; Rokem, J S; Goldberg, I; Pines, O ^[1]

---

1. The Hebrew Univ., Jerusalem (Israel)

Cloning of the Saccharomyces cerevisiae FUM1 gene downstream of the strong GAL10 promoter resulted in inducible overexpression of fumarase in the yeast. The overproducing strain exhibited efficient bioconversion of fumaric acid to L-malic acid with an apparent conversion value of 88% and a conversion rate of 80.4 mmol of fumaric acid/h per g of cell wet weight, both of which are much higher than parameters known for industrial bacterial strains. The only product of the conversion reaction was L-malic acid, which was essentially free of the unwanted by-product succinic acid. The GAL10 promoter situated upstream of a promoterless FUM1 gene led to production and correct distribution of the two fumarase isoenzyme activities between cytosolic and mitochondrial subcellular fractions. The amino-terminal sequence of fumarase contains the mitochondrial signal sequence since (i) 92 of 463 amino acid residues from the amino terminus of fumarase are sufficient to localize fumarase-lacZ fusions to mitochondria and (ii) fumarase and fumarase-lacZ fusions lacking the amino-terminal sequence are localized exclusively in the cytosol. The possibility that both mitochondrial and cytosolic fumarases are derived from the same initial translation product is discussed.

• OSTI ID: 6273188
• Journal Information: Applied and Environmental Microbiology; (USA), Vol. 56:9; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HYDRO-LYASES
DNA-CLONING
MALIC ACID
BIOSYNTHESIS
BIOCONVERSION
FUMARIC ACID
MOLECULAR BIOLOGY
SACCHAROMYCES CEREVISIAE
CARBON-OXYGEN LYASES
CARBOXYLIC ACIDS
CLONING
DICARBOXYLIC ACIDS
DNA HYBRIDIZATION
ENZYMES
EUMYCOTA
FUNGI
HYBRIDIZATION
HYDROXY ACIDS
LYASES
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PLANTS
SACCHAROMYCES
SYNTHESIS
YEASTS
550200* - Biochemistry