Cold shock domain of the human Y-box protein YB-1. Backbone dynamics and equilibrium between the native state and a partially unfolded state |
| |
Authors: | Kloks Cathelijne P A M Tessari Marco Vuister Geerten W Hilbers Cornelis W |
| |
Institution: | NSRIM Centre, Faculty of Science, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands. |
| |
Abstract: | The three-dimensional structure of the central cold shock domain (CSD) of the human Y-box protein (YB-1 CSD) is virtually identical to those available for the bacterial cold shock proteins (Csp's). We have further characterized YB-1 CSD by studying its dynamics by nuclear magnetic resonance. The observed structural similarity is reflected in the backbone dynamics, which for YB-1 CSD is very similar to that of the Escherichia coli protein CspA. The rotational correlation time of YB-1 CSD shows that it is a monomer. This indicates that the dimerization observed for the YB-1 protein is not caused by its CSD, but involves other parts of this protein. The YB-1 CSD is only marginally stable as are the mesophilic bacterial Csp's. In contrast to the rapid two-state folding of the bacterial Csp's, the formation of the native form of YB-1 CSD is slow and at least a three-state process. The NMR experiments revealed the presence of a second state of YB-1 CSD in equilibrium with the native form. The exchange rates from and to the folded state are in the order of 0.2 and 0.5 s(-1), respectively. Relaxation experiments indicated that the second state is a highly flexible, partly structured molecule. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|