FIG 2.

Characteristics of M. tuberculosis BlaC that make it broadly applicable as a biomarker to detect infection. (A) Amino acid sequence alignment of the M. tuberculosis BlaC with the β-lactamases present in tuberculosis complex bacteria showing that the protein sequence is completely conserved in all bacteria that can cause tuberculosis in humans and Mycobacterium tuberculosis subsp. bovis bacillus Calmette-Guérin (BCG). Motifs I, II, and III that are present in class A β-lactamases are marked by green, red, and blue boxes, respectively, on the alignment (47, 54). (B) Amino acid sequence alignment with a diverse set of other β-lactamases. Boxed amino acids within this alignment indicate unique glycine residues found in the amino acid sequence for BlaC. (C) Phylogenetic tree illustrating the evolutionary distances between M. tuberculosis BlaC and other selected β-lactamases. The scale bar denotes the distance equivalent to 0.8 generations for the phylogenetic tree.