Delta(3,5)-Delta(2,4)-dienoyl-CoA isomerase from rat liver - Molecular characterization

Summary, in English

rECH1, a recently identified rat cDNA (FitzPatrick, D. R., Germain-Lee, E., and Valle, D. (1995) Genomics 27, 457-466) encodes a polypeptide belonging to the hydratase/isomerase superfamily, We modeled the structure of rECH1 based on rat mitochondrial 2-enoyl-CoA hydratase 1, The model predicts that rECH1p has the hydratase fold in the core domain and two domains for interaction with other subunits. When we incubated 3,5,8,11,14-eicosapentaenoyl-CoA with purified rECH1p, the spectral data suggested a switching of the double bonds from the Delta(3)-Delta(5) to the Delta(2)-Delta(4) positions. This was confirmed by demonstrating that the product was a valid substrate for 2,4-dienoyl-CoA reductase, These results indicate that rECH1p is Delta(3,5)-Delta(2,4)-dienoyl-CoA isomerase, Subcellular fractionation and immunoelectron microscopy using antibodies to a synthetic polypeptide derived from the C terminus of rECH1p showed that rECH1p is located in the matrix of both mitochondria and peroxisomes in rat liver, Consistent with these observations, the 36,000-Da rECH1p has a potential N-terminal mitochondrial targeting signal as well as a C-terminal peroxisomal targeting signal type 1, Transport of the protein into the mitochondria with cleavage of the targeting signal results in a mature mitochondrial form with a molecular mass of 32,000 Da; transport to peroxisomes yields a protein of 36,000 Da.

• Author: SA Filppula; AI Yagi; SH Kilpelainen; D Novikov; DR FitzPatrick; Mauno Vihinen; D Valle; JK Hiltunen
• Publishing year: 1998
• Language: English
• Pages: 349-355
• Publication/Series: Journal of Biological Chemistry
• Volume: 273
• Issue: 1
• Links: http://dx.doi.org/10.1074/jbc.273.1.349
• Document type: Journal article
• Publisher: American Society for Biochemistry and Molecular Biology
• Topic: Medical Genetics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1083-351X