Genetic context of sigH and σH-like genes in members of the Firmicutes. The figure was generated using Microbes on line facilities http://www.microbesonline.org. Similarly filled arrows represent homologous CDSs. White arrows indicate CDSs without counterpart. Pseudogene is indicated by a dotted outline. RNA-encoding genes are represented by thin arrows. Two loci are shown for L. salivarius, one demonstrating the absence of a sigH counterpart in the same genetic context as B. subtilis and the other, at a distance of 0.9 Mb, showing the sigH homologous gene in its genetic context. Two loci are also shown for S. pneumoniae, which possesses two identical copies of comX. Positions of primers AML50 (upstream) and AML58 (downstream) are indicated by small arrows under the L. sakei sigH locus. Species are represented by the same strains as listed in Figure 2.