FIG. 1.

Alignment of the PvdS protein with Fur-controlled putative ECF sigma factors (PbrA, PfrI, PupI, and FecI), stress response sigma factors (AlgU and RpoE), and the primary sigma (RpoD). The sequences were translated from the GenBank entries given in parentheses: P. aeruginosa PvdS (U128919) and AlgU (L021119), P. fluorescens PbrA (X79908), P. putida PfrI (X82038) and PupI (X77918), and E. coli FecI (U14003), RpoE (U37089), and RpoD (J016887). For RpoD, the N-terminal 85 residues and a 254-residue nonconserved sequence (nc) between regions 1 and 2 are not shown. Regions 2, 3, and 4 of RpoD, conserved among the ς⁷⁰ family (23), are shown below the alignment. Conserved residues among the entire data set are highlighted in reverse type. Shaded areas indicate conserved residues among the ECF family. Conserved residues among the Fur-controlled ECF sigma factors are boxed. Identical residues and the following sets of residues are considered matched: DE; NQ; RK; ST; FYW; ILVM. Plus signs and asterisks indicate amino acid positions selected for construction of maximum-likelihood trees.