1q90
From Proteopedia
| |||||||
| , resolution 3.10Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , , , , , | ||||||
| Gene: | PETA (Chlamydomonas reinhardtii), PETB (Chlamydomonas reinhardtii), PETC (Chlamydomonas reinhardtii), PETD (Chlamydomonas reinhardtii), PETG (Chlamydomonas reinhardtii), PETL (Chlamydomonas reinhardtii), PETM (Chlamydomonas reinhardtii), PETN (Chlamydomonas reinhardtii) | ||||||
| Activity: | Plastoquinol--plastocyanin reductase, with EC number 1.10.99.1 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of the cytochrome b6f (plastohydroquinone : plastocyanin oxidoreductase) from Chlamydomonas reinhardtii
Overview
Photosystems I and II (PSI and II) are reaction centres that capture light energy in order to drive oxygenic photosynthesis; however, they can only do so by interacting with the multisubunit cytochrome b(6)f complex. This complex receives electrons from PSII and passes them to PSI, pumping protons across the membrane and powering the Q-cycle. Unlike the mitochondrial and bacterial homologue cytochrome bc(1), cytochrome b(6)f can switch to a cyclic mode of electron transfer around PSI using an unknown pathway. Here we present the X-ray structure at 3.1 A of cytochrome b(6)f from the alga Chlamydomonas reinhardtii. The structure bears similarities to cytochrome bc(1) but also exhibits some unique features, such as binding chlorophyll, beta-carotene and an unexpected haem sharing a quinone site. This haem is atypical as it is covalently bound by one thioether linkage and has no axial amino acid ligand. This haem may be the missing link in oxygenic photosynthesis.
About this Structure
1Q90 is a Protein complex structure of sequences from Chlamydomonas reinhardtii. Full crystallographic information is available from OCA.
Reference
An atypical haem in the cytochrome b(6)f complex., Stroebel D, Choquet Y, Popot JL, Picot D, Nature. 2003 Nov 27;426(6965):413-8. PMID:14647374
Page seeded by OCA on Sun Mar 30 23:10:27 2008
Categories: Chlamydomonas reinhardtii | Plastoquinol--plastocyanin reductase | Protein complex | Choquet, Y. | Picot, D. | Popot, J L. | Stroebel, D. | Beta-carotene | Chlorophyll | Electron transfer | Membrane protein complex | Monogalactosyldiacylglycerol | Oxydoreductase | Photosynthesis | Stigmatellin | Sulfoquinovosyldiacylglycerol
