Molecular Mechansims of Sec-Mediated Protein Translocation
Sprache der Bezeichnung:
Living organisms are built of cells that are surrounded by and contain membranes consisting of lipids. Proteins are another important class of biological molecules. They are responsible for keeping all the biochemical processes running that a living cell needs to survive. Many of these proteins have to be transported through membranes, a process called translocation, or they have to be inserted into the membrane and, therefore, are referred to as membrane proteins. These tasks are fulfilled by particular membrane proteins, the translocons, which form special channels in the membranes. In the present project, we would like to understand the molecular mechanisms of the translocation process. In particular, we would like to know, how the channel decides, whether a given protein is transported through the membrane or inserted into it. Another problem is that many proteins, that have to be transported through the membrane, contain charged amino acids, thus, bearing charged groups. Such groups are normally repelled from the membrane, and the question arises of how the translocon deals with these cases. In the project, these questions will be tackled by computer modelling of the translocon located in the membrane of bacteria (called SecY). The structure of the bacterial channel will be taken from an open-access protein data bank. Then, special software packages will be used to put the translocon into a membrane and model movements of all atoms of the system, thereby mimicking the function of the channel. In addition, experimental studies of the translocation process will be performed by our collaborators. Since similar channels also exist in human cells, we expect important insights into the working principles of translocons that might become the basis for medical applications in the future.