FIG 5 .

Immunoprecipitation coupled with LC-MS/MS analysis identifies potential MagD partners, including three proteins encoded by the mag operon. (A) Silver-stained SDS-polyacrylamide gel showing the steps of IP experiments. Immunopurified anti-MagD antibodies were used with parental (PAO1 ΔretS) and ΔmagD strains. Twenty microliters of the input (lanes I), washing fraction (lanes W), and eluate (lanes E) were analyzed by SDS-PAGE and revealed by silver staining. Molecular masses (MM) are in kDa. (B) Immunoanalysis of the input, washing fraction, and eluate by anti-MagD polyclonal antibodies showing the presence of MagD only in the eluate of the parental strain. Following LC-MS/MS analysis (Table 1), the same fractions were analyzed for the presence of three proteins encoded within the operon, namely, MagA, MagB, and MagF.