Sequence alignment and crystal structure of E . coli PmrD. (A) Sequence alignment between the PmrD proteins of E. coli and other bacteria. The results of the sequence alignment are represented as conservation, quality, and consensus using the Clustal Omega program. All sequences were obtained from NCBI. (E. coli PmrD, NP_416762.2; S. enterica PmrD, NP_456847.1; Shigella flexneri PmrD, NP_708145.1; KP-PmrD, YP_002237594.1). (B) Crystal structure of E. coli PmrD. The overall structure of E. coli PmrD is exhibited as a ribbon model. The secondary structures are indicated by the one α-helix (α1), six β-strands (β1, β2, β3, β4, β5, and β6), and loops in the ribbon model.