Abstract
In plants and cyanobacteria, the primary step in oxygenic photosynthesis, the light induced charge separation, is driven by two large membrane intrinsic protein complexes, the photosystems I and II. Photosystem I catalyses the light driven electron transfer from plastocyanin/cytochrome c6 on the lumenal side of the membrane to ferredoxin/flavodoxin at the stromal side by a chain of electron carriers. Photosystem I of Synechococcus elongatus consists of 12 protein subunits, 96 chlorophyll a molecules, 22 carotenoids, three [4Fe4S] clusters and two phylloquinones. Furthermore, it has been discovered that four lipids are intrinsic components of photosystem I. Photosystem I exists as a trimer in the native membrane with a molecular mass of 1068 kDa for the whole complex. The X-ray structure of photosystem I at a resolution of 2.5 Å shows the location of the individual subunits and cofactors and provides new information on the protein-cofactor interactions. [P. Jordan, P. Fromme, H.T. Witt, O. Klukas, W. Saenger, N. Krauß, Nature 411 (2001) 909-917]. In this review, biochemical data and results of biophysical investigations are discussed with respect to the X-ray crystallographic structure in order to give an overview of the structure and function of this large membrane protein.
Original language | English |
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Pages (from-to) | 5-31 |
Number of pages | 27 |
Journal | Biochimica et Biophysica Acta - Bioenergetics |
Volume | 1507 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - Oct 30 2001 |
Keywords
- Core antenna
- Electron transfer chain
- Membrane protein
- Photosystem I
- Structure
- X-ray crystallography
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Cell Biology