EMBO Fellows Meeting 2012

Niti Kumar
EMBO Fellows Meeting 2012
Understanding nascent chain conformation
Abstract
The linear array of amino acids harbors the information specifying the structure and function of newlysynthesized
polypeptides. Nascent polypeptides emerging from the ribosome may undergo co-translational
folding depending on the number of residues exposed outside the ribosome tunnel. Interactions between the
nascent chain and ribosome tunnel components may modulate the conformational search for attainment of
the folded state. However, our information on nascent chain folding is still limited. To gain insight into this
process, we are employing both biophysical and biochemical tools to map the conformational status of Titin
nascent chains of different lengths. Specifically, we are monitoring FRET between the nascent chain and the
ribosome, using donor in the nascent chain and acceptor in the ribosome. Our measurements show that Titin
folds when the entire protein domain is exposed outside the tunnel, consistent with its adoption of a protease
resistant conformation. This approach can be used to analyze the conformational dynamics and stability of
different polypeptides under a variety of conditions.
Niti Kumar, Sathish Kumar Lakshmipathy, Raluca Antonoaea, Ulrich Hartl
Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
14-17 June 2012, Heidelberg, Germany