FIG. 1.

Conserved TonB Box IV, amino acid motifs, and amino acid residues in the P. gingivalis HmuR protein. (A) Homology between the P. gingivalis HmuR and the TonB box IV regions of several different heme and hemoglobin receptors and siderophore and vitamin B₁₂ receptors. The E. coli TonB consensus sequence is also depicted. (B) Homology between the P. gingivalis HmuR protein and the carboxy-terminal region of several different heme and hemoglobin receptors and siderophore and vitamin B₁₂ receptors. Conserved amino acids between the P. gingivalis HmuR and the consensus sequence are indicated by boldface letters. The numbers indicate the position in the unprocessed protein of the first amino acid listed. Pg, P. gingivalis; Vv, V. vulnificus; Vc, V. cholerae; Sd, S. dysenteriae; Ye, Y. enterocolitica; Hi, H. influenzae; Hd, H. ducreyi; Nm, N. meningitidis; Pf, P. fluorenscens; and Pa, P. aeruginosa.