4H13
Crystal Structure of the Cytochrome b6f Complex from Mastigocladus laminosus with TDS
Summary for 4H13
| Entry DOI | 10.2210/pdb4h13/pdb |
| Related | 1Q90 1VF5 2E76 4H0L 4H44 |
| Descriptor | Cytochrome b6, PROTOPORPHYRIN IX CONTAINING FE, (7R,17E)-4-HYDROXY-N,N,N,7-TETRAMETHYL-7-[(8E)-OCTADEC-8-ENOYLOXY]-10-OXO-3,5,9-TRIOXA-4-PHOSPHAHEPTACOS-17-EN-1-AMINIUM 4-OXIDE, ... (22 entities in total) |
| Functional Keywords | alpha helix, beta sheet, plastoquinol-plastocyanin oxidoreductase, plastocyanin, thylakoid membrane, photosynthesis |
| Biological source | Mastigocladus laminosus (Fischerella sp.) More |
| Cellular location | Cellular thylakoid membrane; Multi-pass membrane protein: P83791 P83792 Cellular thylakoid membrane; Single-pass membrane protein: P83793 P83795 P83796 P83797 P83798 Cellular thylakoid membrane; Single-pass membrane protein (By similarity): P83794 |
| Total number of polymer chains | 8 |
| Total formula weight | 117209.61 |
| Authors | Hasan, S.S.,Yamashita, E.,Baniulis, D.,Cramer, W.A. (deposition date: 2012-09-10, release date: 2013-02-13, Last modification date: 2023-11-08) |
| Primary citation | Hasan, S.S.,Yamashita, E.,Baniulis, D.,Cramer, W.A. Quinone-dependent proton transfer pathways in the photosynthetic cytochrome b6f complex Proc.Natl.Acad.Sci.USA, 110:4297-4302, 2013 Cited by PubMed Abstract: As much as two-thirds of the proton gradient used for transmembrane free energy storage in oxygenic photosynthesis is generated by the cytochrome b6f complex. The proton uptake pathway from the electrochemically negative (n) aqueous phase to the n-side quinone binding site of the complex, and a probable route for proton exit to the positive phase resulting from quinol oxidation, are defined in a 2.70-Å crystal structure and in structures with quinone analog inhibitors at 3.07 Å (tridecyl-stigmatellin) and 3.25-Å (2-nonyl-4-hydroxyquinoline N-oxide) resolution. The simplest n-side proton pathway extends from the aqueous phase via Asp20 and Arg207 (cytochrome b6 subunit) to quinone bound axially to heme c(n). On the positive side, the heme-proximal Glu78 (subunit IV), which accepts protons from plastosemiquinone, defines a route for H(+) transfer to the aqueous phase. These pathways provide a structure-based description of the quinone-mediated proton transfer responsible for generation of the transmembrane electrochemical potential gradient in oxygenic photosynthesis. PubMed: 23440205DOI: 10.1073/pnas.1222248110 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3.07 Å) |
Structure validation
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