PDBsum entry 2bns

Photosynthesis

PDB id: 2bns

Contents

Protein chains

281 a.a. *

302 a.a. *

237 a.a. *

Ligands

BCL ×4

BPH ×2

MST

U10

PO4 ×2

Metals

FE2

_CL

Waters ×94

* Residue conservation analysis

PDB id:

2bns

Name:

Photosynthesis

Title:

Lipidic cubic phase grown reaction centre from rhodobacter sphaeroides, excited state

Structure:

Reaction center protein l chain. Chain: a. Synonym: photosynthetic reaction center l subunit. Reaction center protein m chain. Chain: b. Synonym: photosynthetic reaction center m subunit. Reaction center protein h chain. Chain: c. Synonym: photosynthetic reaction center h subunit

Source:

Rhodobacter sphaeroides. Organism_taxid: 1063. Strain: r26. Strain: r26

Biol. unit:

Trimer (from PDB file)

Resolution:

2.50Å R-factor: 0.211 R-free: 0.247

Authors:

G.Katona,A.Snijder,P.Gourdon,U.Andreasson,O.Hansson,L.E.Andreasson, R.Neutze

Key ref:

G.Katona et al. (2005). Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center. Nat Struct Mol Biol, 12, 630-631. PubMed id: 15937492 DOI: 10.1038/nsmb948

Date:

31-Mar-05 Release date: 27-May-05

Protein chain

P0C0Y8  (RCEL_CERSP) -  Reaction center protein L chain from Cereibacter sphaeroides

Seq: 282 a.a.

Struc: 281 a.a.

Protein chain

P0C0Y9  (RCEM_CERSP) -  Reaction center protein M chain from Cereibacter sphaeroides

Seq: 308 a.a.

Struc: 302 a.a.

Protein chain

P0C0Y7  (RCEH_CERSP) -  Reaction center protein H chain from Cereibacter sphaeroides

Seq: 260 a.a.

Struc: 237 a.a.

DOI no: 10.1038/nsmb948

Nat Struct Mol Biol 12:630-631 (2005)

PubMed id: 15937492

Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center.

G.Katona, A.Snijder, P.Gourdon, U.Andréasson, O.Hansson, L.E.Andréasson, R.Neutze.

ABSTRACT

In bright light the photosynthetic reaction center (RC) of Rhodobacter sphaeroides stabilizes the P(+)(870).Q(-)(A) charge-separated state and thereby minimizes the potentially harmful effects of light saturation. Using X-ray diffraction we report a conformational change that occurs within the cytoplasmic domain of this RC in response to prolonged illumination with bright light. Our observations suggest a novel structural mechanism for the regulation of electron transfer reactions in photosynthesis.

Selected figure(s)

Figure 1.
Figure 1. Electron transfer reactions within the RC. Time scales are indicated. In bright light the recombination of the P+[870] Q-[A] charge-separated state is slowed from 100 ms to 250 s (red arrow).

Figure 2.
Figure 2. Structural changes within the RC in response to bright light. (a) Reproducible difference electron density features (yellow, negative density; blue, positive density) are large spheres (observed in all six difference Fourier maps) and small spheres (observed in five of six). Statistics are given in Supplementary Table 2 online. Arginines with increased trypsin susceptibility in bright light are red, and those with decreased susceptibility are blue. The H subunit is cyan. (b) Refined structural changes. Arrowheads indicate the relative magnitude and direction of the movements (blue, positively charged residues; red, negatively charged residues; gray, every fifth residue). Surface-exposed histidines are green, buried water molecules red and the C-terminal -helix gray. The subdomain from Pro121H to Thr226H (purple) experiences a net electrostatic force (yellow vector) due to interactions with Q-[A] (red).

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Mol Biol (2005, 12, 630-631) copyright 2005.