National Institutes of Health/National Human Genome Research Institute
RO1AI134054
米国
引用
ジャーナル: Biochemistry / 年: 2019 タイトル: Exploits a Heterohexameric Enoyl-CoA Hydratase Retro-Aldolase Complex for Cholesterol Catabolism. 著者: Tianao Yuan / Meng Yang / Kalle Gehring / Nicole S Sampson / 要旨: Cholesterol catabolism plays an important role in 's ('s) survival and persistence in the host. exploits three β-oxidation cycles to fully degrade the side chain of cholesterol. Five cistronic ...Cholesterol catabolism plays an important role in 's ('s) survival and persistence in the host. exploits three β-oxidation cycles to fully degrade the side chain of cholesterol. Five cistronic genes in a single operon encode three enzymes, 3-oxo-4-pregnene-20-carboxyl-CoA dehydrogenase (ChsE1-ChsE2), 3-oxo-4,17-pregnadiene-20-carboxyl-CoA hydratase (ChsH1-ChsH2), and 17-hydroxy-3-oxo-4-pregnene-20-carboxyl-CoA retro-aldolase (Ltp2), to perform the last β-oxidation cycle in this pathway. Among these three enzymes, ChsH1-ChsH2 and Ltp2 form a protein complex that is required for the catalysis of carbon-carbon bond cleavage. In this work, we report the structure of the full length ChsH1-ChsH2-Ltp2 complex based on small-angle X-ray scattering and single-particle electron microscopy data. Mutagenesis experiments confirm the requirement for Ltp2 to catalyze the retro-aldol reaction. The structure illustrates how acyl transfer between enzymes may occur. Each protomer of the ChsH1-ChsH2-Ltp2 complex contains three protein components: a chain of ChsH1, a chain of ChsH2, and a chain of Ltp2. Two protomers dimerize at the interface of Ltp2 to form a heterohexameric structure. This unique heterohexameric structure of the ChsH1-ChsH2-Ltp2 complex provides entry to further understand the mechanism of cholesterol catabolism in .