Figure 2.

CLUSTAL-W sequence alignment of (A) ²FNIII and the five closest structural homologs of ²FNIII as identified by Dali (Holm and Sander, 1998), and (B) ¹⁻²FNIII sequences from different FN proteins. The residue spans of ¹FNIII and ²FNIII are denoted by brackets, and the positions of the two amino-acid substitutions engineered in this study, K669A and D767A, are indicated by arrows. Highlighted by yellow bars are the three ²FNIII residues (E726, I802 and L803) identified in our analysis as possibly responsible for the disordered ²FNIII N-terminus, and their sequence counterparts in other domains. Highlighted in a purple box are the residues of the disordered ¹FNIII–²FNIII linker in all FN molecules. Shown in a cyan box are residues of the interdomain linker removal of which adversely affects the ¹⁻²FNIII–FN30 kDa interaction.