Alignment of integrin  subunits between the type III and IV homologous repeats. The alignment was created using the UWGCG program “pretty.” The amino acid sequences of the integrin  subunits are shown using the single letter code. Alanine substitutions are indicated (*). The boundaries of exon 5 of _IIb are indicated by vertical lines. Bold letters indicate residues with oxygen containing side chains. CN, consensus sequence.