Figure 2. emm3 isolates have a 13 base pair (bp) deletion within the smeZ locus.

Representation of the smeZ locus from emm1 (M1) and emm3 (M3) strains. Nucleotides 1 to 3 encode the start codon (shown in bold). From 73 bp of the nucleotide sequence, the amino acid sequence of the mature SMEZ protein is shown. Emm3 strains have a 13 bp deletion at 316 bp (highlighted by a shaded box) that results in a frameshift and a predicted premature stop codon after 86 amino acids (shown as *). The forward primer and the reverse primer amplify the full length smeZ locus. The 13 bp deletion was detected using a forward (truncated) primer that anneals specifically to the region containing the deletion.