Genotyping of the cagA variable EPIYA motif. (A) Schematic representation of the cagA variable region. Western CagA (EPIYA-ABC) is depicted on the top, and East Asian CagA (EPIYA-ABD) is depicted on the bottom. The annealing positions (small arrows), names of the primers used in this study, and expected sizes (large arrows) of the amplified specific EPIYA motif products as based on the strain K3-CA DNA sequence are shown. Primer names are abbreviated as follows: cagA28F, A28F; cag2, 2; cagA-P1C, P1C; cagA-pA-1 (R), A; cagA-P2TA, P2TA; cagA-P2CG, P2CG; cagA-P3E, P3E; and cagA-pD (R), D. (B) PCR amplicons of K49-DU and K3-CA using the forward primer 2 and the reverse primer A, P2TA and P2CG (equimolar mixture), P3E, or D. “M” designates the size markers (in base pairs). Type indicates the resulting EPIYA motif identified. (C) Amino acid alignment of the carboxy terminus of CagA from 29 Korean strains carrying the EPIYA-ABD motif. The EPIYA-A, -B, and -D motifs are indicated below the consensus sequence.