Molecular Characterization of Saccharomyces cerevisiae Δ3,Δ2-Enoyl-CoA Isomerase

doi:10.1074/jbc.273.50.33184

Molecular Characterization of Saccharomyces cerevisiae Δ³,Δ²-Enoyl-CoA Isomerase*

From the Departments of ^‡Biological Chemistry and ^‖Pediatrics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, the ^§Department of Chemistry, City College, City University of New York, New York, New York 10031, and the ^¶Department of Physiological Chemistry, Ruhr-Universitat Bochum, 44780 Bochum, Germany

Abstract

We report here the identification of theSaccharomyces cerevisiae peroxisomal Δ³,Δ²-enoyl-CoA isomerase, an enzyme that is essential for the β-oxidation of unsaturated fatty acids. The yeast gene YLR284C was identified in an in silico screen for genes that contain an oleate response element, a transcription factor-binding site common to most fatty acid-induced genes. Growth on oleic acid resulted in a significant increase inYLR284C mRNA, demonstrating that it is indeed an oleate-induced gene. The deduced product of YLR284Ccontains a type 1 peroxisomal targeting signal-like sequence at its C terminus and localizes to the peroxisome in aPEX8-dependent manner. Removal ofYLR284C from the S. cerevisiae genome eliminated growth on oleic acid, but had no effect on peroxisome biogenesis, indicating a role for YLR284C in fatty acid metabolism. Cells lacking YLR284C had no detectable Δ³,Δ²-enoyl-CoA isomerase activity, and a bacterially expressed form of this protein catalyzed the isomerization of 3-cis-octenoyl-CoA to 2-trans-octenoyl-CoA with a specific activity of 16 units/mg. We conclude thatYLR284C encodes the yeast peroxisomal Δ³,Δ²-enoyl-CoA isomerase and propose a new name, ECI1, to reflect its enoyl-CoA isomerase activity.

Footnotes

↵* This work was supported by National Institutes of Health Grant DK45787 (to S. J. G.) and by Deutsche Forschungsgemeinschaft Grant ERA78/2-1 (to R. E.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) AF090442.
↵** To whom correspondence should be addressed: Dept. of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205. Tel.: 410-955-3085; Fax: 410-955-0215; E-mail: Stephen.Gould{at}qmail.bs.jhu.edu.
↵2 M. T. Geraghty, D. E. Bassett, J. C. Morrell, G. J. Gatto, J. Bai, B. V. Geisbrecht, P. T. Hieter, and S. J. Gould, submitted for publication.
Abbreviations:

PTS

peroxisomal targeting signal

ORE

oleate response element

ORF

open reading frame

PCR

polymerase chain reaction

GFP

green fluorescent protein

MBP

maltose-binding protein

MES

4-morpholineethanesulfonic acid.
- Received August 12, 1998.
- Revision received September 10, 1998.
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