title: Organization of the multifunctional enzyme type 1: interaction between N- and C-terminal domains is required for the hydratase-1/isomerase activity.
abstract: Rat peroxisomal multifunctional enzyme type 1 (perMFE-1) is a monomeric protein of beta-oxidation. We have defined five functional domains (A, B, C, D and E) in the perMFE-1 based on comparison of the amino acid sequence with homologous proteins from databases and structural data of the hydratase-1/isomerases (H1/I) and (3 S )-hydroxyacyl-CoA dehydrogenases (HAD). Domain A (residues 1-190) comprises the H1/I fold and catalyses both 2-enoyl-CoA hydratase-1 and Delta(3)-Delta(2)-enoyl-CoA isomerase reactions. Domain B (residues 191-280) links domain A to the (3 S )-dehydrogenase region, which includes both domain C (residues 281-474) and domain D (residues 480-583). Domains C and D carry features of the dinucleotide-binding and the dimerization domains of monofunctional HADs respectively. Domain E (residues 584-722) has sequence similarity to domain D of the perMFE-1, which suggests that it has evolved via partial gene duplication. Experiments with engineered perMFE-1 variants demonstrate that the H1/I competence of domain A requires stabilizing interactions with domains D and E. The variant His-perMFE (residues 288-479)Delta, in which the domain C is deleted, is stable and has hydratase-1 activity. It is proposed that the extreme C-terminal domain E in perMFE-1 serves the following three functions: (i) participation in the folding of the N-terminus into a functionally competent H1/I fold, (ii) stabilization of the dehydrogenation domains by interaction with the domain D and (iii) the targeting of the perMFE-1 to peroxisomes via its C-terminal tripeptide.
authors.affiliation: Biocenter Oulu and Department of Biochemistry, University of Oulu, P.O. Box 3000, FIN-90014, Finland.
authors.forename: Tiila-Riikka
authors.initials: TR
authors.lastname: Kiema
authors.forename: Jukka P
authors.initials: JP
authors.lastname: Taskinen
authors.forename: Päivi L
authors.initials: PL
authors.lastname: Pirilä
authors.forename: Kari T
authors.initials: KT
authors.lastname: Koivuranta
authors.forename: Rik K
authors.initials: RK
authors.lastname: Wierenga
authors.forename: J Kalervo
authors.initials: JK
authors.lastname: Hiltunen
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D004746:Enoyl-CoA Hydratase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D007535:Isomerases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D063994:Peroxisomal Bifunctional Enzyme; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship
chemical_list: D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D015094:3-Hydroxyacyl CoA Dehydrogenases; D004746:Enoyl-CoA Hydratase; D063994:Peroxisomal Bifunctional Enzyme; D007535:Isomerases