Assembly of the Type II Secretion System such as Found in Vibrio cholerae Depends on the Novel Pilotin AspS
(A) Ribbon representation of the structure of V. cholerae AspS. α-helices, α1–α4, are in crimson; β-strands, β1–β5, are in light blue. Zn2+ ions are shown as grey spheres. Acetate ions are shown in stick representation. Residues coordinating Zn2+ and acetate ions are in stick representation with oxygen and nitrogen atoms color-coded red and blue, respectively. The position of the disulphide bond Cys74–Cys111 is shown. (B) A superposition of AspS (light blue) and PA3611 (orange) structures in ribbon representation. Note the outward movement of β-strands β1 and β2 in PA3611 structure. (C) Electrostatic surface potential of PA3611 structure (positive = blue; negative = red). The buffer CAPS molecules are shown in stick representation.