Fig. 6.

Model of hGBP1_F function. After binding of GTP to hGBP1_F and release of the farnesyl anchor, hGBP1_F may follow two cycles: membrane binding with further membrane tethering (Left cycle) or polymerization by formation of a disk in a first phase accompanied by slow GTP hydrolysis followed by stacking of the circular structures to cylindrical structures enabling faster GTP turnover (Right cycle). See the text for more details. (Inset) With the subdomains highlighted in different colors, schematic representation of hGBP1 is according to the crystal structure of nonfarnesylated protein in the nucleotide-free state (Protein Data Bank ID code 1DG3). The farnesyl anchor at the C terminus is depicted as a blue zigzag line (ellipse).