Evaluation of acyl coenzyme A oxidase (Aox) isozyme function in the n- alkane-assimilating yeast Yarrowia lipolytica
ABSTRACT We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n -alkane-assimilating yeast Yarrowia lipolytica , encoded by the POX1 through POX5 genes. The physiological function of these oxidases has been investigated by gene disruption. Single, double, triple, and quadruple disruptants were constructed. Global Aox activity was determined as a function of time after induction and of substrate chain length. Single null mutations did not affect growth but affected the chain length preference of acyl-CoA oxidase activity, as evidenced by a chain length specificity for Aox2 and Aox3. Aox2 was shown to be a long-chain acyl-CoA oxidase and Aox3 was found to …
Involvement of acyl coenzyme A oxidase isozymes in biotransformation of methyl ricinoleate into gamma-decalactone by Yarrowia lipolytica.
ABSTRACT We reported previously on the function of acyl coenzyme A (acyl-CoA) oxidase isozymes in the yeast Yarrowia lipolytica by investigating strains disrupted in one or several acyl-CoA oxidase-encoding genes ( POX1 through POX5 ) (H. Wang et al., J. Bacteriol. 181:5140–5148, 1999). Here, these mutants were studied for lactone production. Monodisrupted strains produced similar levels of lactone as the wild-type strain (50 mg/liter) except for Δ pox3 , which produced 220 mg of γ-decalactone per liter after 24 h. The Δ pox2 Δpox3 double-disrupted strain, although slightly affected in growth, produced about 150 mg of lactone per liter, indicating that Aox2p was not essential for the biotra…
Cloning and characterization of the peroxisomal acyl CoA oxidaseACO3 gene from the alkane-utilizing yeastYarrowia lipolytica
The ACO3 gene, which encodes one of the acyl-CoA oxidase isoenzymes, was isolated from the alkane-utilizing yeast Yarrowia lipolytica as a 10 kb genomic fragment. It was sequenced and found to encode a 701-amino acid protein very similar to other ACOs, 67.5% identical to Y. lipolytica Aco1p and about 40% identical to S. cerevisiae Pox1p. Haploid strains with a disrupted allele were able to grow on fatty acids. The levels of acyl-CoA oxidase activity in the ACO3 deleted strain, in an ACO1 deleted strain and in the wild-type strain, suggested that ACO3 encodes a short chain acyl-CoA oxidase isoenzyme. This narrow substrate spectrum was confirmed by expression of Aco3p in E. coli.