Figure 1.

The psm-mec locus and its products. (A) The psm-mec gene is located on the class A mecA complex in SCCmec elements of types II, III, and VIII, next to the mecI/mecR1/mecA genes that confer methicillin resistance and its regulation. (B) The PSM-mec peptide product of the psm-mec locus forms an α-helix with pronounced amphiphathy; helical wheel presentation. (C) The psm-mec gene is part of a regulatory RNA with pronounced predicted secondary structure. The psm-mec gene is entirely embedded in a highly folded, large stem loop. The psm-mec srRNA only slightly extends toward the 3′ end and ends with a characteristic predicted terminator stem loop structure (Note, however, that Kaito et al. reported the srRNA to be slightly longer at the 5′ end). RBS, ribosomal binding site; Start codon coding for (N-formyl) methionine.