| Autor: |
Steimle S; Department of Biology, University of Pennsylvania, Philadelphia, PA, USA., van Eeuwen T; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA., Ozturk Y; Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.; Institute of Biochemistry and Molecular Biology, Faculty of Medicine, Albert-Ludwigs University of Freiburg, Freiburg, Germany., Kim HJ; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA., Braitbard M; School of Computer Science and Engineering, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel., Selamoglu N; Department of Biology, University of Pennsylvania, Philadelphia, PA, USA., Garcia BA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA., Schneidman-Duhovny D; School of Computer Science and Engineering, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel., Murakami K; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. kenjim@pennmedicine.upenn.edu., Daldal F; Department of Biology, University of Pennsylvania, Philadelphia, PA, USA. fdaldal@sas.upenn.edu. |
| Abstrakt: |
Respiratory electron transport complexes are organized as individual entities or combined as large supercomplexes (SC). Gram-negative bacteria deploy a mitochondrial-like cytochrome (cyt) bc 1 (Complex III, CIII 2 ), and may have specific cbb 3 -type cyt c oxidases (Complex IV, CIV) instead of the canonical aa 3 -type CIV. Electron transfer between these complexes is mediated by soluble (c 2 ) and membrane-anchored (c y ) cyts. Here, we report the structure of an engineered bc 1 -cbb 3 type SC (CIII 2 CIV, 5.2 Å resolution) and three conformers of native CIII 2 (3.3 Å resolution). The SC is active in vivo and in vitro, contains all catalytic subunits and cofactors, and two extra transmembrane helices attributed to cyt c y and the assembly factor CcoH. The cyt c y is integral to SC, its cyt domain is mobile and it conveys electrons to CIV differently than cyt c 2 . The successful production of a native-like functional SC and determination of its structure illustrate the characteristics of membrane-confined and membrane-external respiratory electron transport pathways in Gram-negative bacteria. |
Full text from SpringerLink