PHOTORINGS · Photosynthesis: What controls the membrane protein Ring Size?
6РП — Действия „Мария Кюри“
- Период
- 2006-01-30 → 2007-11-29
- Финансиране от ЕС
- 205 474 €
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- 1
- Схема
- EIF
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Накратко на български
Протеините, които улавят светлина при пурпурните бактерии, образуват пръстени от различен размер и брой елементи. Разбирането на тези структури помага да се разберат факторите, които определят формата на всеки такъв комплекс.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - PHOTORINGS (Photosynthesis: What controls the membrane protein Ring Size?)
This fellowship demonstrated that the Light-harvesting (LH) integral membrane proteins from photosynthetic purple bacteria, though amongst the most widely studied, still had much to reveal. The use of different biochemical and spectroscopic techniques showed that the LH2 complexes from purple sulphur photosynthetic bacteria exhibited a certain number of marked differences with their homologues, the LH2 from non-purple sulphur photosynthetic bacteria. In particular, the LH2 complexes from allochromatium had certain properties approaching those of LH1 complexes. This was interesting since the structures of LH2 and LH1 complexes, while based on the same principle, were very different. The association of small peptide heterodimers into closed ringed structures created all these complexes. Whereas LH1 formed rings of 16 heterodimers, LH2 complexes were made of only eight or nine heterodimers. Therefore the rings were of very different sizes. We estimated the size of the LH2 from allochromatium DSM180 and strongly suggested that it was made of 13 heterodimers, being thus intermediate in size between 'normal' LH1s and LH2s. The discovery of this new form of peptide association further opened the way to eventually understand the determining factors that guided the quaternary structure for any given light-harvesting complex.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
During the last decade life sciences have witnessed a spectacular progress in structural biology with the structures of many important biomolecules coming available. However, up to now, only a few structures of membrane proteins have been determined, even although as many as 20 to 40% of the genes of all sequenced genomes code for such macromolecules.Photosynthetic membrane proteins have been at the forefront of membrane protein science, because they generally bind chlorophyll and carotenoid cofactors. The electronic and vibrational properties of these cofactors tightly depend on the precise structure of the proteins to which they are bound and the interactions between them.The presence of these cofactors thus allows the use of a wide range of non-invasive, state-of-the-art spectroscopic techniques to control and to study their structure and dynamics in relation to their function. This unique property explains why most of the breakthroughs in membrane protein science, from the first isolation of a highly pure and functionally active membrane protein, to the solving of the first structure of a membrane protein, have been achieved with proteins from the photosynthetic membrane.The light-harvesting pigments used in purple bacterial photosynthesis are organised into two types of integral membrane pigment-protein complexes, called reaction centres and antenna complexes. Light absorbed by the antenna complexes in transferred to the reaction centres where it is trapped. The antenna complexes are all oligomers of dimers.These dimers consist of apoproteins together with the pigments. The antenna oligomers are all circular structures and, so far, rings with 8, 9 and 16 dimers have been described. A major question is what controls ring size? The proposal sets out t o answer this by a detailed comparison of LH2 complexes that have different ring sizes.
Оригинален текст от CORDIS (на английски).
Участници
- COMMISSARIAT A L'ENERGIE ATOMIQUE · GIF SUR YVETTEКоординаторФранция
Връзки
Данни: CORDIS, © Европейски съюз