Location of GP Ibx mutations. (A) Alignment of the leucine-rich repeats (LRRs) of human, canine, and murine GP Ibα. The 11 conserved charged amino acids are indicated by asterisks. The β strands in the LRRs of GP Ibα are highlighted. (B) Location of residues mutated in the current study within the structure of the GP Ibα N-terminus. Acidic residues appear in red; basic residues appear in blue.