3A0B

Crystal structure of Br-substituted Photosystem II complex

Summary for 3A0B

• Entry DOI: 10.2210/pdb3a0b/pdb
• Related: 3A0H
• Descriptor: Photosystem Q(B) protein, Photosystem II reaction center protein K, Photosystem II reaction center protein L, ... (31 entities in total)
• Functional Keywords: multi-membrane protein complex, electron transport, herbicide resistance, iron, membrane, metal-binding, photosynthesis, photosystem ii, thylakoid, transmembrane, transport, heme, reaction center
• Biological source: Thermosynechococcus vulcanus (Synechococcus vulcanus); More
• Cellular location: Cellular thylakoid membrane; Multi-pass membrane protein: P51765; Cellular thylakoid membrane; Single-pass membrane protein: P12241; Cellular thylakoid membrane; Single-pass membrane protein (By similarity): P12313 P12238 P12239 Q7DGD4; Cellular thylakoid membrane; Peripheral membrane protein; Lumenal side: P0A387
• Total number of polymer chains: 40
• Total formula weight: 683970.90

Authors

Kawakami, K.,Umena, Y.,Kamiya, N.,Shen, J.-R. (deposition date: 2009-03-16, release date: 2009-05-19, Last modification date: 2024-10-23)

Primary citation

Kawakami, K.,Umena, Y.,Kamiya, N.,Shen, J.-R.
Location of chloride and its possible functions in oxygen-evolving photosystem II revealed by X-ray crystallography
Proc.Natl.Acad.Sci.USA, 106:8567-8572, 2009

PubMed Abstract: The chloride ion, Cl(-), is an essential cofactor for oxygen evolution of photosystem II (PSII) and is closely associated with the Mn(4)Ca cluster. Its detailed location and function have not been identified, however. We substituted Cl(-) with a bromide ion (Br(-)) or an iodide ion (I(-)) in PSII and analyzed the crystal structures of PSII with Br(-) and I(-) substitutions. Substitution of Cl(-) with Br(-) did not inhibit oxygen evolution, whereas substitution of Cl(-) with I(-) completely inhibited oxygen evolution, indicating the efficient replacement of Cl(-) by I(-). PSII with Br(-) and I(-) substitutions were crystallized, and their structures were analyzed. The results showed that there are 2 anion-binding sites in each PSII monomer; they are located on 2 sides of the Mn(4)Ca cluster at equal distances from the metal cluster. Anion-binding site 1 is close to the main chain of D1-Glu-333, and site 2 is close to the main chain of CP43-Glu-354; these 2 residues are coordinated directly with the Mn(4)Ca cluster. In addition, site 1 is located in the entrance of a proton exit channel. These results indicate that these 2 Cl(-) anions are required to maintain the coordination structure of the Mn(4)Ca cluster as well as the proposed proton channel, thereby keeping the oxygen-evolving complex fully active.

PubMed: 19433803
DOI: 10.1073/pnas.0812797106

Experimental method

X-RAY DIFFRACTION (3.7 Å)