ClustalX alignment and consensus amino acid sequences of Msp2 hypervariable domains. Domains were translated from genomic and RT-PCR amplicons of A. phagocytophilum Webster strain msp2 after 7 and 20 passages in vitro. The alignment demonstrates the heterogeneity of the hypervariable domains and the lack of significant similarities that would suggest combinatorial gene conversion as a mechanism for ongoing Msp2 antigenic variation. Paralog names are listed on the left, the total number of amino acid residues is shown on the right; the consensus sequence is shown on the bottom – "." indicates a semi-conserved position, ":" indicates a highly conserved position, and "*" indicates a conserved position.