Fig. S8.

Sequence alignment of the ZP-N/ZP-C linker region of the ZP module. All sequences are human. Elements are depicted as in Fig. S3. Non-Cys residues are colored according to their physicochemical properties: positive, blue; negative, red; aromatic, purple; Pro/Gly, orange; hydrophobic, brown; polar, green. Note how the linker (red) between the ZP-N domain (blue) and the ZP-C domain (which starts with the IHP, gray) is either very short or completely absent in nonpolymerizing proteins BG and ENG.