Co-translational mechanisms of protein folding studied on the single molecule level

• Applicants: Professor Dr. Jörg Fitter; Dr. Alexandros Katranidis
• Subject Area: Biophysics ; Biochemistry
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 426150054

Co-translational protein folding is coupled to protein synthesis and is mediated by spatial constraints and interactions within as well as outside the ribosomal tunnel. However, it is still not yet entirely understood how synthesis (i.e. polypeptide chain elongation) and folding cooperate to accomplish a fully functional protein. Our previous work provided us the required technical knowledge and experience to bring together force- and fluorescence-based single-molecule techniques in order to achieve a deeper understanding of this interconnection. More specifically we plan to focus on three topics. In topic one, following the latest evidence from literature, we intent to study in more depth the co-translational folding of a small protein domain inside the ribosomal tunnel combining smFRET and optical tweezers. In topic two we plan to incorporate in a co-translational manner fluorophores suitable for smFRET in order to characterize nascent chains of different length of a two-domain protein (Phosphoglycerate kinase), corresponding to different stages of synthesis and folding. Finally in topic three we aim to go one step further and plan to observe synthesis and folding of the two-domain protein in real time making use of both force and smFRET measurements and trying to identify the sequence of folding events in relation with certain stages of translation.

• DFG Programme: Research Grants