Figure 2.

X-ray structures of the self-complemented FimA monomers. A, cartoon representations of FimA^ECO (gray), FimA^SHI (blue), and FimA^SAL (green) X-ray structures, with the N-terminal donor strand highlighted in red. B, surface representation of the three FimA monomer structures, highlighting the surface complementarity between the donor strands (red) and the FimA folds. C, global superposition of the donor strand conformations in all structures. In contrast to the structures of FimA^ECO and FimA^SAL, the residues occupying the pockets P4 and P5 are separated by two residues in the FimA^SHI structure. The sequences of all three donor strands are indicated. The unresolved region of FimA^ECO donor strand is shown as a dotted line.