The membrane-binding residues of the F-BAR domains and the equivalent residues in CagA. The structures are shown for the F-BAR domains from human FCHo2 (available in the Protein Data Bank (PDB) under code 2v0o ), human PSTPIP1 (homology model generated using the above structure 2v0o as a template), and for CagA fragment 261–829 (PDB code 4dvz ). The homology region is coloured blue. The side chains of the membrane-binding residues of the F-BAR domains that are conserved in CagA are shown as blue sticks and labelled. The four-helical bundle in CagA that shares structural similarities with proteins that interact with actin-regulatory networks  is encircled with a green dashed line. The side chain of E634 in CagA is coloured red to highlight the site with positive selection .