FIG 4.

Neither the CAAX motifs nor the C-terminal domain is required for LyrA function. (A to C) The contribution of the three conserved CAAX protease motif residues (E135, R139, and H210) and the conserved non-CaaX protease R196 residue was tested by expressing alanine (A) substitution variants from a plasmid in the lyrA mutant. The new strains were analyzed for lysostaphin resistance (A), SpA production (B), and length of glycan strands (C). (D to F) The contribution of the C-terminal domain of LyrA was tested by expressing a variant encompassing only the 8 transmembrane segments (lyrA-TM) from a plasmid in the lyrA mutant. The new strains were analyzed for lysostaphin resistance (D), SpA production (E), and length of glycan strands (F).