FIG 1 .

Genetic organization of fim operons in S. enterica serovar Typhimurium and E. coli K-12 and of the sfm operon of E. coli K-12. The fimA (sfmA) and fimH (sfmH) genes are shown in pink and yellow, respectively. The remaining structural fimbrial genes are shown in light gray. The genes involved in regulation are shown in dark gray and tRNA-Arg genes in green. The percent identity for corresponding DNA and protein sequences was determined by pairwise alignment (BioEdit). Chromosomal locations of the operons are designated by numbers below the designations of the neighboring genes of the operons (boxed). “PDE” indicates gene STM0551 encoding phosphodiesterase. The phage-related genes are marked by double slashes (//).