Type 2A mutations. (A) Positions of VWD type 2A missense mutations mapped onto the structure of VWF D1-A1 as it occurs in a tubule. (B) Y87 lines a crevice in the VWD1 domain. The type 2A VWD mutation Y87S would allow solvent into this crevice, potentially disrupting tubule formation. (C) R202 forms intra- and intermolecular interactions with 2 additional VWF molecules denoted in purple and dark teal. R202W, a mutation causing type 2A VWD, would disrupt these interactions. A dashed green line shows a π–cation bond. (D) A1 domain in light pink with residues altered in type 2A VWD colored in dark pink. Leucine residues described in the text are labeled.