Schematic of wild-type GP Ibα and the mutant produced by the dinucleotide deletion of the second 2 bases of the codon for Tyr492 (TAT). The mutation shifts the translation reading frame beginning approximately 7 amino acids into the GP Ibα transmembrane domain. The new polypeptide sequence is indicated by the underlined italic portion. The full-length mutant is 38 amino acids shorter than wild-type GP Ibα.