RNA POLYMERASE III · Structural studies of yeast RNA polymerase III
6РП — Действия „Мария Кюри“
- Период
- 2007-06-01 → 2009-05-31
- Финансиране от ЕС
- 148 588 €
- Участници
- 1
- Схема
- EIF
Линиите свързват координатора с партньорите. За проекти отпреди 2014 г. CORDIS не винаги дава точни координати. Тези точки са на ниво град или държава.
Накратко на български
Структурата на РНК полимераза III при дрождите се анализира чрез електронна микроскопия, за да се види как този ензим синтезира малки РНК молекули. Това помага за разбирането на механизмите, по които клетката регулира транскрипцията на своите гени.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - RNA POLYMERASE III (Structural studies of yeast RNA polymerase III)
During gene transcription, RNA is synthesised from a DNA template by DNA-dependent RNA polymerases (Pols). Eukaryotic cells contain three nuclear RNA polymerases, which are responsible for the synthesis of ribosomal RNA (Pol I), pre-messenger RNA (Pol II) and small RNAs including transfer RNAs (Pol III). The three RNA polymerases differ in subunit composition, reflecting their evolutionary specialisation in transcription of different genes and suggesting their independent regulation. Genes of different classes differ in promoter structure, which dictates assembly of the specific Pol with class-specific general transcription factors (initiation factors) into a preinitiation complex. With a total molecular weight of nearly 700 kDa, Pol III is the largest and the most complex nuclear RNA polymerase. As stated in the original working plan, we managed to establish large-scale fermentation (200 liters) and purification of Pol III from S. cerevisiae. By means of cryo-electron microscopy and crystallography (hybrid approach) we were able to obtain three independent snapshot of Pol III: first, the apo-enzyme in isolation, second, the complex with a specific Pol III gene (elongation complex) and third, a complex with the global negative regulator Maf1. These reconstructions are of high quality and allowed us to rationalize the specific features of the Pol III enzyme and its activity, supporting previously published biochemical data, now on a structural level. Upon completion of functional in vitro data experiments to corroborate our model, we will be able to publish our findings in a high-impact journal, given the importance of such basic mechanisms that are of central importance for the whole transcription regulation community.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
During gene transcription, RNA is synthesized from a DNA template by DNA-dependent RNA polymerases (Pols). Eukaryotic cells contain three nuclear RNA polymerases, responsible for the synthesis of ribosomal RNA (Pol I), pre-messenger RNA (Pol II) and small RNAs including transfer RNAs (Pol III). The three RNA polymerases differ in subunits composition.Whereas Pol II has 12 subunits, Pol III consists of 17 subunits ranging from 10 to 160 kDa. With a total molecular weight of nearly 700 kDa, Pol III is the largest and the most complex nuclear RNA polymerase. Of the 17 Pol III subunits, ten are unique to Pol III, five are common to all three eukaryotic RNA polymerases, and two are shared by Pol I and III.Whereas the crystal structure of Pol II is known, and a n electron microscopic structure of Pol I is available, there is no structural data on Pol III, despite its important roles in regulating cell growth and differentiation.Here we propose to study the three-dimensional structure of the Pol III enzyme by X-r ay crystallography, to obtain novel insights into the mechanisms of transcription, the specific features of Pol III structure and function compared to the Pol II system, and into the evolution of the transcription machineries.Pol III will be purified from yeast strains, and crystals of the entire complex will be sought with the use of a nanoliter robot. Complexes of Pol III with initiation factors and nucleic acids will be prepared for future analysis by cryo-electron microscopy. The studies will benefit from the expertise on Pol II structure determination in the institute.A structural description of Pol III will be of central importance to the large community concerned with gene expression and its regulation, and will contribute to the further development of structural biology techniques. The longer-term goal of this project is to unravel the determinants for promoter specificity of the three nuclear polymerases.
Оригинален текст от CORDIS (на английски).
Участници
- LUDWIG-MAXIMILIANS-UNIVERSITY MUENCHEN · MUENCHENКоординаторНиво градГермания
Връзки
Данни: CORDIS, © Европейски съюз