TY - JOUR
T1 - Δ3,5-Δ2,4-dienoyl-CoA isomerase from rat liver. Molecular characterization
AU - Filppula, S. A.
AU - Yagi, A. I.
AU - Kilpeläinen, S. H.
AU - Novikov, D.
AU - FitzPatrick, D. R.
AU - Vihinen, M.
AU - Valle, D.
AU - Hiltunen, J. K.
PY - 1998/1/2
Y1 - 1998/1/2
N2 - 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 Δ3-Δ5 to the Δ2-Δ4 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 Δ3,5-Δ2,4-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.
AB - 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 Δ3-Δ5 to the Δ2-Δ4 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 Δ3,5-Δ2,4-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.
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U2 - 10.1074/jbc.273.1.349
DO - 10.1074/jbc.273.1.349
M3 - Article
C2 - 9417087
AN - SCOPUS:0031594712
SN - 0021-9258
VL - 273
SP - 349
EP - 355
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 1
ER -