FIG. 1.

Amino acid sequence alignment of the p28 proteins of five E. chaffeensis human isolates. The complete amino acid sequence of the Arkansas strain is presented as the consensus sequence. Differences from the consensus sequence are presented in lowercase. Dots represent the amino acids identical to those of the Arkansas strain, and dashes indicate gaps which were introduced for optimal alignment of the amino acid sequences. The variable regions (VR1, VR2, and VR3) are underlined. The arrow indicates the cleavage site of the signal peptide. The N-terminal portion of the St. Vincent strain sequence is incomplete. Ark, Arkansas; HE, 91HE17; Sap, Sapulpa; Stv, St. Vincent.