RC-LH1 core complex from R. palustris
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RC-LH1 core complex from R. palustris Neil Isaacs Department of Chemistry University of Glasgow
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RC-LH1 core complex from R. palustris. Neil Isaacs Department of Chemistry University of Glasgow. Periplasm. Light. Cytochrome b/c 1. H +. LH2. LH1. e -. e -. H +. Cyt c. Q. Q. B850. B880. e -. Q. RC. Q. Q. Q. B800. Q B. Q. ADP + P i. ATP. H +. H +. Cytoplasm. - PowerPoint PPT Presentation
Transcript of RC-LH1 core complex from R. palustris
RC-LH1 core complex from R. palustrisNeil Isaacs
Department of Chemistry
University of Glasgow
ATP synthase
ATPADP + Pi
H+
H+
H+
H+
LH2 LH1
RC
Light
Cyt c
Q
Q
Q
Q Q
Qe-
e-e-
B800
B850 B880
Cytochrome b/c1
Cytoplasm
Periplasm
QB
Q
Photosynthetic system of purple bacteria
Peripheral light-harvesting antenna (LH2 complex) from Rh. Acidophila, McDermott et al. (1995) Nature 374, 517.
Shown above is the structure of RC from Rhodobacter sphaeroides, Allen, et al. (1987) PNAS, 84, 5730; McAuley, et al. (1999) PNAS, 96, 14706.
First structure of reaction centre, from Rhodopseudomonas viridis, was determined by Deisenhofer, et al. (1985) Nature 318, 618.
The Bacterial Reaction Centre
Cytochrome bc1(Iwata et al (1998) Science, 281, 64—71)
F1ATPase Abrahams et al, (1994) Nature, 370, 621--8
ATP synthase
ATPADP + Pi
H+
H+
H+
H+
LH2 LH1
RC
Light
Cyt c
Q
Q
Q
Q Q
Qe-
e-e-
B800
B850 B880
Cytochrome b/c1
Cytoplasm
Periplasm
QB
Q
Karrasch et al. (1995) EMBO J., 14, 631.
Electron Microscopy 8.5 Å projection map for 2D-crystalof the reconstituted light-harvesting complex I (LH1) fromRhodospirillum rubrum.
Hypothetical model of the purple bacteria PSU
Papiz MZ, Prince SM, Hawthornthwaite-Lawles AM, McDermott G, Freer AA, Isaacs NW & Cogdell RJ (1996) Trends Plant Sci. 1, 198-206.
LH1
RC
LH2
Walz, et al. (1998) J. Mol. Biol. 282, 833.
Electron Microscopy 25 Å projections for 2D-crystals of the RC-LH1 complex from Rhodobacter sphaeroides.
Diffraction from crystals of the LH1-RC core complex
Current electron density map
QB
W
S. Bahatyrova et al, (2004) Nature, 430, 1058-1062
AFM shows the arrangement of photosynthetic complexes in the membrane
Questions to tax the brain:
What is protein W?
How does LH1 interact with RC?
How does W interact with RC and LH1?
How does the complex assemble?
34 proteins 2 Ubiquinone
19 Bchl 16? Carotenoid
2 Pheophytin Fe
> 70 components & no instructions….
LH60 column of Rps. palustris 'French' core complex
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 20 40 60 80 100 120
Fraction Number
Ab
sorb
an
ce (
280n
m)
RC polypeptides
LH polypeptidesPigments/phospholipids
W?
Separation of organic solvent soluble polypeptides
LH1-RC core
6.5
14
21 -dimers
-polypeptide
-polypeptide10
15
20
W?
6.5
14
21
SDS-PAGE of purified low-molecular weight LH polypeptides
The crystal structure of the RC LH1 core complex from
Rhodopseudomonas palustris
Aleksander W. Roszak, Tina D. Howard, June Southall, Alastair T. Gardiner, Neil W. Isaacs and Richard J. Cogdell
BBSRC Wellcome Trust
SRS Daresbury, stations14.1 and 9.6
Questions:What is protein W?
How does LH1 interact with RC?
How does W interact with RC and LH1?
How does the complex assemble?
34 proteins 2 Ubiquinone
19 Bchl 16? Carotenoid
2 Pheophytin Fe
> 70 components & no instructions….
Cytochrome bc1(Iwata et al (1998) Science, 281, 64—71)
F1ATPase Abrahams et al, (1994) Nature, 370, 621--8
