Alignment of vWF-A1and vWF-A2 sequences from 28 mammalian species. The sequences are identified by accession numbers. The numbering is taken from human vWF, and the location of α-helices and β-strands follows that of Fig 1. Residues that are 100% absolutely or conservatively conserved are indicated by an asterisk. (Conservative: G=A=S, D=E, I=L=V=M; S=T, R=K=H, F=Y=W=H; X is disregarded). (A) The positions of D520 and E626 at the active site and the proposed heparin site RK-RR-K (residues 571-585) are marked by a dollar sign ($). The positions of the type 2B and 2M mutations are marked by a number sign (#). (B) The position of D744 at the active site and the protease cleavage site at Y842-M843 are marked by $. The positions of the type 2A mutations are marked by #. The positions of two conserved putative N-linked glycosylation sites are marked by N.