AMINO-ACID-SEQUENCE SIMILARITIES OF THE MITOCHONDRIAL SHORT CHAIN DELTA-3,DELTA-2-ENOYL-COA ISOMERASE AND PEROXISOMAL MULTIFUNCTIONAL DELTA-3,DELTA-2-ENOYL-COA ISOMERASE, 2-ENOYL-COA HYDRATASE, 3-HYDROXYACYL-COA DEHYDROGENASE ENZYME IN RAT-LIVER - THE PROPOSED OCCURRENCE OF ISOMERIZATION AND HYDRATION IN THE SAME CATALYTIC DOMAIN OF THE MULTIFUNCTIONAL ENZYME

Research output: Contribution to journalArticle

Abstract

We report the isolation and characterization of a cDNA encoding the mitochondrial short chain DELTA-3,DELTA-2-enoyl-CoA isomerase from rat liver. Tryptic fragments of the purified protein were generated, purified, and sequenced. A rat liver cDNA library, constructed in the plasmid vector pUEX1 was screened with oligonucleotides synthesized on the basis of peptide sequences. The obtained clone contained 783 bases predicting to code the entire mature protein of 261 amino acids. The molecular weight of 29,300 predicted from cDNA-derived sequences was consistent with the subunit size determined earlier. A high degree of similarity was noted between the amino acid sequence of isomerase and that of the amino-terminal half of peroxisomal multifunctional isomerase-hydratase-dehydrogenase enzyme and mitochondrial 2-enoyl-CoA hydratase in rat liver. These similarities also appeared at the level of predicted secondary structural elements, suggesting that the rat multifunctional enzyme has both the isomerization and hydration activities in the amino-terminal domain. This idea is further supported by the proposed existence of only one CoA-binding site in the amino-terminal half of the multifunctional enzyme and by previous studies suggesting that the transfer of the substrate from the isomerization site to the hydration site occurs without aqueous bulk phase (Palosaari P. M., and Hiltunen, J. K. (1990) J. Biol. Chem. 265, 2446-2449).

Details

Authors
  • PM PALOSAARI
  • Mauno Vihinen
  • PI MANTSALA
  • SEH ALEXSON
  • T PIHLAJANIEMI
  • JK HILTUNEN
External organisations
  • External Organization - Unknown
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Medical Genetics
Original languageEnglish
Pages (from-to)10750-10753
JournalJournal of Biological Chemistry
Volume266
Issue number17
Publication statusPublished - 1991
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes