Figure 1.

Fibrinogen and its C-terminal γ subunit sequences. (a) Ribbon diagram of fibrinogen (Yang et al., 2001) with α, β, and γ subunits in green, red, and blue, respectively, and natively unstructured C-terminal regions of the α and γ subunits (Yang et al., 2001; Doolittle and Kollman, 2006) that contain RGD and KQAGDV sequences shown schematically as dashed lines. (b) The C-terminal sequence of the γ subunit in different species. Basic and acidic residues that are important for binding to fibrinogen as shown here for human and implicated for other species are shown in red. Gln and Lys residues known (human and lamprey; Strong et al., 1985) or implicated (other species) to mediate fibrinogen cross-linking catalyzed by factor XIIIa transglutaminase are underlined. Sequence accession (GI) numbers of the relevant fibrinogen splice variants are 70906437, 73977998, 19527078, 61098186, 45384500, 120145, and 120143.