Characterization of protein import channel-forming proteins in chloroplasts [Elektronische Ressource] / Erika Kovács-Bogdán. Betreuer: Jürgen Soll

Characterization of protein import channel-forming proteins in chloroplasts Dissertation der Fakultät für Biologie der Ludwig-Maximilians-Universität München vorgelegt von Erika Kovács-Bogdán aus Budapest, Ungarn München, den 09.05.2011 Erstgutachter: Prof. Dr. Jürgen Soll Zweitgutachter: Prof. Dr. Michael Schleicher Tag der mündlichen Prüfung: 08. Juli 2011 2 Abstract Most chloroplast proteins are encoded for in the nucleus and have to be transported into the organelle after translation in the cytoplasm. The TOC and TIC machineries (Translocon at the Outer/Inner envelope membrane of Chloroplasts) mediate the import of these proteins across the chloroplast membranes. The major aim of this work was to characterize two TIC translocon components: Tic110, the main protein translocation channel in the inner envelope, and Tic20, which was proposed to also form a protein import channel. After a detailed study of Tic110, a topological model could be established, demonstrating that the protein is inserted into the membrane with two hydrophobic and four amphipathic helices, placing residues both to the intermembrane space and to the stromal side.