FIG 5.

Cys¹⁹⁹ and His²⁵⁴ are required for EssH murein hydrolase activity. (A) Coomassie brilliant blue-stained SDS-PAGE gel separating purified _STREPEssH (1) and _STREPEssH^C199A/H254A (2). The other numbers indicate the migratory positions of molecular weight markers (in kilodaltons). (B) Purified S. aureus peptidoglycans were digested with mutanolysin and split into three samples that were either left untreated (black trace) or were treated with _STREPEssH (red trace) or _STREPEssH^C199A/H254A (green trace); the carbohydrates in all samples were reduced and analyzed by reversed-phase HPLC.