Molecule of the Month
April 2023
Length does matter

The tripartite attachment complex (TAC) in T. brucei physically connects the base of the flagellum to the single unit mitochondrial DNA. The >200nm long cytosolic TAC-region is spanned by a single protein. p197 is 660kDa in size, mostly alpha-helical and defines the distance between the base of the flagellum and the outer mitochondrial membrane.
We used ultrastructure expansion microscopy (U-ExM) to monitor the topology of p197 and its function as a spacer protein.

This work was a collaborative effort by the group of Prof. Dr. André Schneider (DCBP) and the group of Prof. Dr. Torsten Ochsenreiter (IZB).


  • S. Aeschlimann, A. Kalichava, B.d Schimanski, B. M. Berger, C. Jetishi, P. Stettler, T. Ochsenreiter, A. Schneider;
    "Single p197 molecules of the mitochondrial genome segregation system of Trypanosoma brucei determine the distance between basal body and outer membrane"
    PNAS, 2022, 119(40), e2204294119/1-10; doi:10.1073/pnas.2204294119.