Fig. 2.
Overall topology of AspA-C2–3. (A) Ribbon diagram of AspA-C2–3 presented in stereo. The C2 domain (residues 971–1150) is depicted in blue while the C3 domain (1151–1306) is depicted in yellow. A bound calcium ion is shown as a grey sphere. (B) Topology diagram of AspA-C2–3 where α-helices are represented as rectangles, β-strands as arrows and loops as lines. The isopeptide bonds between K987 and N1128 and between K1155 and N1286 are marked as red lines. (C) Electrostatic surface potential rendering of AspA-C2–3 colored from −0.5 V (red) to 0.5 V (blue). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)