FIG 4.

Serotype M3 GAS isolates harbor a 1-bp deletion in rivR that results in a truncated protein. (A) Schematic of a region of the rivR gene in M1 GAS and also of the corresponding region, which contains a 1-bp deletion, in M3 GAS. The homopolymeric tract that contains the 1-bp deletion in M3 GAS is highlighted with horizontal green bars. The premature stop codon introduced into the rivR gene of serotype M3 GAS by the 1-bp deletion is shown in red (TAA). (B) Comparison of the rivR open reading frames in M1 and M3 GAS isolates. Note the truncated rivR gene in M3 GAS. (C) Domain structure of the RivR protein. The locations of putative helix-turn-helix (HTH; green), winged helix-turn-helix (wHTH; orange), and phosphotransferase system regulatory (PRD; blue) domains are shown. The red asterisk shows the relative location of the truncation in serotype M3 isolates.