1ikt | pdb_00001ikt
LIGANDED STEROL CARRIER PROTEIN TYPE 2 (SCP-2) LIKE DOMAIN OF HUMAN MULTIFUNCTIONAL ENZYME TYPE 2 (MFE-2)
Structural highlights
DiseaseDHB4_HUMAN Defects in HSD17B4 are a cause of D-bifunctional protein deficiency (DBPD) [MIM:261515. DBPD is a disorder of peroxisomal fatty acid beta-oxidation.[1] [2] [3] Defects in HSD17B4 are the cause of Perrault syndrome (PRLTS1) [MIM:233400. A sex-influenced disorder characterized by sensorineural deafness in both males and females and ovarian dysgenesis in females. Some patients also have neurologic manifestations, including mild mental retardation and cerebellar and peripheral nervous system involvement.[4] FunctionDHB4_HUMAN Bifunctional enzyme acting on the peroxisomal beta-oxidation pathway for fatty acids. Catalyzes the formation of 3-ketoacyl-CoA intermediates from both straight-chain and 2-methyl-branched-chain fatty acids.[5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedbeta-Oxidation of amino acyl coenzyme A (acyl-CoA) species in mammalian peroxisomes can occur via either multifunctional enzyme type 1 (MFE-1) or type 2 (MFE-2), both of which catalyze the hydration of trans-2-enoyl-CoA and the dehydrogenation of 3-hydroxyacyl-CoA, but with opposite chiral specificity. MFE-2 has a modular organization of three domains. The function of the C-terminal domain of the mammalian MFE-2, which shows similarity with sterol carrier protein type 2 (SCP-2), is unclear. Here, the structure of the SCP-2-like domain comprising amino acid residues 618-736 of human MFE-2 (d Delta h Delta SCP-2L) was solved at 1.75 A resolution in complex with Triton X-100, an analog of a lipid molecule. This is the first reported structure of an MFE-2 domain. The d Delta h Delta SCP-2L has an alpha/beta-fold consisting of five beta-strands and five alpha-helices; the overall architecture resembles the rabbit and human SCP-2 structures. However, the structure of d Delta h Delta SCP-2L shows a hydrophobic tunnel that traverses the protein, which is occupied by an ordered Triton X-100 molecule. The tunnel is large enough to accommodate molecules such as straight-chain and branched-chain fatty acyl-CoAs and bile acid intermediates. Large empty apolar cavities are observed near the exit of the tunnel and between the helices C and D. In addition, the C-terminal peroxisomal targeting signal is ordered in the structure and solvent-exposed, which is not the case with unliganded rabbit SCP-2, supporting the hypothesis of a ligand-assisted targeting mechanism. Crystal structure of the liganded SCP-2-like domain of human peroxisomal multifunctional enzyme type 2 at 1.75 A resolution.,Haapalainen AM, van Aalten DM, Merilainen G, Jalonen JE, Pirila P, Wierenga RK, Hiltunen JK, Glumoff T J Mol Biol. 2001 Nov 9;313(5):1127-38. PMID:11700068[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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