4I7Z: Crystal structure of cytochrome b6f in DOPG, with disordered Rieske Iron-Sulfur Protein soluble domain

Citation:
Abstract
Cytochrome b6f catalyzes quinone redox reactions within photosynthetic membranes to generate a transmembrane proton electrochemical gradient for ATP synthesis. A key step involves the transfer of an electron from the [2Fe-2S] cluster of the iron-sulfur protein (ISP) extrinsic domain to the cytochrome f heme across a distance of 26 A, which is too large for competent electron transfer but could be bridged by translation-rotation of the ISP. Here we report the first crystallographic evidence of significant motion of the ISP extrinsic domain. It is inferred that extensive crystallographic disorder of the ISP extrinsic domain indicates conformational flexibility. The ISP disorder observed in this structure, in contrast to the largely ordered ISP structure observed in the b6f complex supplemented with neutral lipids, is attributed to electrostatic interactions arising from anionic lipids.
PDB ID: 4I7ZDownload
MMDB ID: 109215
PDB Deposition Date: 2012/12/1
Updated in MMDB: 2013/12
Experimental Method:
x-ray diffraction
Resolution: 2.803  Å
Source Organism:
Similar Structures:
Biological Unit for 4I7Z: hexadecameric; determined by author and by software (PISA)
Molecular Components in 4I7Z
Label Count Molecule
Proteins (16 molecules)
2
Cytochrome B6
Molecule annotation
2
Cytochrome B6-f Complex Subunit 4
Molecule annotation
2
Apocytochrome F
Molecule annotation
2
Cytochrome B6-f Complex Iron-sulfur Subunit
Molecule annotation
2
Cytochrome B6-f Complex Subunit 6
Molecule annotation
2
Cytochrome B6-f Complex Subunit 7
Molecule annotation
2
Cytochrome B6-f Complex Subunit 5
Molecule annotation
2
Cytochrome B6-f Complex Subunit 8
Molecule annotation
Chemicals (38 molecules)
1
8
2
2
3
2
4
6
5
6
6
2
7
6
8
2
9
2
10
2
* Click molecule labels to explore molecular sequence information.

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