View source for 2ux3

[[Image:2ux3.gif|left|200px]]<br />
<applet load="2ux3" size="450" color="white" frame="true" align="right" spinBox="true" 
caption="2ux3, resolution 2.50&Aring;" />
'''X-RAY HIGH RESOLUTION STRUCTURE OF THE PHOTOSYNTHETIC REACTION CENTER FROM RB. SPHAEROIDES AT PH 9 IN THE NEUTRAL STATE'''<br />

==Overview==
The structure of the photosynthetic reaction-center from Rhodobacter, sphaeroides has been determined at four different pH values (6.5, 8.0, 9.0, 10.0) in the neutral and in charge separated states. At pH 8.0, in, the neutral state, we obtain a resolution of 1.87 A, which is the best, ever reported for the bacterial reaction center protein. Our, crystallographic data confirm the existence of two different binding, positions of the secondary quinone (Q(B)). We observe a new orientation of, Q(B) in its distal position, which shows no ring-flip compared to the, orientation in the proximal position. Datasets collected for the different, pH values show a pH-dependence of the population of the proximal position., The new orientation of Q(B) in the distal position and the pH-dependence, could be confirmed by continuum electrostatics calculations. Our, calculations are in agreement with the experimentally observed proton, uptake upon charge separation. The high resolution of our crystallographic, data allows us to identify new water molecules and external residues being, involved in two previously described hydrogen bond proton channels. These, extended proton-transfer pathways, ending at either of the two oxo-groups, of Q(B) in its proximal position, provide additional evidence that, ring-flipping is not required for complete protonation of Q(B) upon, reduction.

==About this Structure==
2UX3 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Rhodobacter_sphaeroides Rhodobacter sphaeroides] with PO4, FE, BCL, LDA, BPH, UQ2, HTO, U10, SPO, CDN and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2UX3 OCA]. 

==Reference==
pH Modulates the Quinone Position in the Photosynthetic Reaction Center from Rhodobacter sphaeroides in the Neutral and Charge Separated States., Koepke J, Krammer EM, Klingen AR, Sebban P, Ullmann GM, Fritzsch G, J Mol Biol. 2007 Aug 10;371(2):396-409. Epub 2007 May 10. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17570397 17570397]
[[Category: Protein complex]]
[[Category: Rhodobacter sphaeroides]]
[[Category: Diehm, R.]]
[[Category: Fritzsch, G.]]
[[Category: Koepke, J.]]
[[Category: BCL]]
[[Category: BPH]]
[[Category: CDN]]
[[Category: FE]]
[[Category: GOL]]
[[Category: HTO]]
[[Category: LDA]]
[[Category: PO4]]
[[Category: SPO]]
[[Category: U10]]
[[Category: UQ2]]
[[Category: bacteriochlorophyll]]
[[Category: binding positions of the secondary quinone qb]]
[[Category: cardiolipin]]
[[Category: chlorophyll]]
[[Category: chromophore]]
[[Category: electron transport]]
[[Category: glucosylgalactosyl diacylglycerol]]
[[Category: iron]]
[[Category: magnesium]]
[[Category: membrane]]
[[Category: metal-binding]]
[[Category: phosphatidylcholine]]
[[Category: photosynthesis]]
[[Category: proton translocation pathways]]
[[Category: reaction center]]
[[Category: transmembrane]]
[[Category: transport]]

''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov  5 14:33:02 2007''