Figure 3.

Sequence alignment of all nine FS domains in chicken agrin. The first FS domain starts with residue number 148. The upper scheme aligns the first four cysteine residues of the FOLN subdomain (disulfide linkage pattern between cysteine residues 1-3 and 2-4), whereas the Kazal subdomain with six cysteines is shown below (disulfide linkage pattern between cysteine residues 5-9, 6-8, and 7-10). Conserved residues within the Kazal subdomain are highlighted. Remarkably, the disulfide linkage between 2nd and 3rd as well as 5th and 9th cysteine residue is interrupted in the FS-3 domain.