Figure 1.

PorX phosphorylation. (A) Phosphorylation of wild type PorX (wt) with ³²P-acetyl phosphate (³²P-AcP). Bovine serum albumin (BSA) was used as a negative control. (B) Size exclusion chromatography (SEC) elution chromatogram of wild-type PorX (blue curve = non-phosphorylated, orange curve = phosphorylated with AcP) in the presence of Mg²⁺. (C, D) SEC-MALLS analysis to determine the absolute MW of wild-type PorX (wt) incubated with (C) MgCl₂ alone (Mg²⁺), required for phosphorylation, and (D) AcP (wt-P) and MgCl₂ (Mg²⁺). The mass fraction of the corresponding peak is shown in parentheses.