Structure and function of cyanobacterial PspA/IM30 proteins

• Applicants: Professor Dr. Carsten Sachse; Professor Dr. Dirk Schneider
• Subject Area: Structural Biology ; Biochemistry ; Biophysics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 504526299

PspA and IM30 (Vipp1), two proteins of bacterial origin, are members of the ESCRT-III super-family of membrane remodeling proteins. Our groups, i.e., the groups of D. Schneider and C. Sachse, have recently jointly solved the structure of a PspA supercomplex by cryo-electron microscopy (cryo-EM) (Cell 2021:184, 3674-3688), the basis for the experiments proposed here. Building on detailed biochemical and biophysical characterization of the IM30 protein of the cyanobacterium Synechocystis sp. PCC 6803, ESCRT biology and the comprehensive cryo-EM expertise, we will now combine biochemical/biophysical experiments with high-resolution structural cryo-EM approaches to describe the details of PspA and IM30 membrane interactions and their respective membrane-protecting and/or membrane-remodeling activities. The proposed research builds on a series of experiments published by us in recent years and will allow us to develop a detailed model of action of PspA and IM30 supported by observed structural states. Based on our recent discovery that these proteins are members of the ESCRT-III protein superfamily, we anticipate that our research on the minimal (bacterial) systems will allow us to better understand the (far more complex) eukaryotic ESCRT-III activity.

• DFG Programme: Research Grants