A New Old Yellow Enzyme of Saccharomyces cerevisiae

Abstract

In 1993, the first gene of Old Yellow Enzyme (OYE) of Saccharomyces cerevisiae was cloned (Stott, K., Saito, K., Thiele, D. J., and Massey, V. (1993) J. Biol. Chem. 268, 6097-6106) and named OYE2 to distinguish it from the first OYE gene cloned from Saccharomyces carlsbergenesis (Saito, K., Thiele, D. J., Davio, M., Lockridge, O., and Massey, V. (1991) J. Biol. Chem. 266, 20720-20724). The analysis of an OYE2 deletion mutant suggested that S. cerevisiae had at least two OYE genes. In the present study, we cloned a new OYE species named OYE3 and analyzed the OYE3 protein expressed in Escherichia coli. OYE3 consists of 400 amino acid residues and its molecular mass calculated by electrospray mass spectrometry is 44,788 daltons, in good agreement with the value of 44,920 daltons predicted from the amino acid sequence derived from the DNA sequence. In the downstream region of the OYE3 gene, the cytochrome oxidase (COX10) gene exists with a 426-base pair intermediate sequence. Some of the physicochemical and kinetic properties of OYE2 and OYE3 have been determined. Although the two enzymes are clearly closely related, they show differences in ligand binding properties and in their catalytic activities with oxygen and cyclohexen-2-one as acceptors.

Old Yellow Enzyme fromCandida macedoniensisCatalyzes the Stereospecific Reduction of the C=C Bond of Ketoisophorone

“…carlsbergensis (OYE1), 14) Sac. cerevisiae (OYE2, OYE3), 15,16) and Schizosaccharomyces pombe (OYEA, OYEB), 17) and estrogen-binding protein of Candida albicans (EBP1) 18) are aligned. Gaps in the aligned sequences are indicated by dashes (").…”

“…An Old Yellow Enzyme was isolated from brewers' yeast as theˆrst ‰avoprotein by Warburg and Christian, 19,20) and has been thoroughly studied by many researchers. [13][14][15][16][21][22][23] However, the application of an Old Yellow Enzyme to a stereospeciˆc reaction, as described here, had not been previously reported. The discovery of this stereospeciˆc reaction by Old Yellow Enzyme might help in elucidation of its reaction mechanism.…”

Role of the non‐respiratory pathways in the utilization of molecular oxygen by Saccharomyces cerevisiae

“…105 Both genes are probably involved in sterol metabolism 188 NADPH is the electron donor to OYEs but the physiological electron acceptors are still unknown. It has been suggested that OYE3 forms H 2 O 2 in the presence of oxygen and NADPH, 144 and that at least one of the two OYEs may contribute to the oxygen consumption observed in the cytosolic fraction. 87,94 However, oxygen is now considered to be an opportunist electron acceptor, as are ferricyanide and methylene blue.…”

The Role of Glutamine 114 in Old Yellow Enzyme

“…Two isozymes of OYE from Saccharomyces cerevisiae, OYE2 and OYE3, which are 91 and 81% identical with the OYE from brewers' bottom yeast, respectively, have been cloned and characterized (8,15). Based on the results of the S. cerevisiae genome sequencing project, it has been established that yeast contains only these two OYE isozymes (16,17).…”