Predicted secondary structure of Ig-like domains of GPVI, compared with a KIR. (A) Alignment of hD1D2 and mD1D2 to KIR2DL1 (pdb code 1NKR⁴² ). Residue numbers are shown above each sequence, either hD1D2 (identical to mD1D2) or KIR2DL1. Identity between sequences is indicated by a star, either below mD1D2 (conserved in human and murine D1D2) or below KIR2DL1 (identity with those conserved residues in D1D2). Predicted β-strands of D1D2 are shown as arrows above hD1D2 (dark blue for D1, light blue for D2). Actual β-strands in 1NKR are shown as white arrows below KIR2DL1. Gaps produced in D1D2 by alignment to KIR2DL1, or the converse, are indicated by hyphens. Cysteines are shown in purple, conserved structural motifs in red, the interdomain linker in blue, and potential N-glycosylation sites in green. Bold type in D1D2 indicates the sites of human-to-murine substitutions. Bold type in KIR2DL1 indicates the sites of interaction with HLA-peptide complex.²¹  (B) Ribbon diagram of hD1D2 model showing the relative positions of residues in hD1D2 that were mutated.