FIG. 1.

The streptococcal metal transport repressor (MtsR). (A) Schematic presentation of the mtsR (spy0450) chromosomal locus in the wild-type strain NZ131. The stem-loop structures represent transcriptional terminators. The genes are represented by their names. The mts genes are annotated as such in the S. pyogenes SF370 genome, while mtsR is annotated as spy0450. (B) CLUSTALW alignment of MtsR (Spy0450) with SloR of S. mutans. White letters on a black background indicate identical residues; white letters on a gray background indicate similar residues. The residues overscored with a single line indicate the helix-turn-helix domain, and those with a double line indicate the FeoA domain. Ancillary metal binding residues (metal site 1) are indicated by the number 1 over the white or black letters, and the primary metalloregulatory residues (metal site 2) are indicated by the number 2. (C) Schematic presentation of the mtsR mutation in ZE491 strain. KmR represents aphA-3, the kanamycin resistance gene, flanked by the Omega transcriptional termination signals (43); mtsRΔ indicates the 5′ portion of mtsR remaining in the ZE491 mutant.