1D SDS-PAGE analysis of purified ApfA and VacJ proteins. Tags were removed from the expressed recombinant proteins by thrombin cleavage. Subsequently, proteins + tags were loaded on an ÄKTAxpress chromatography system and purified by size exclusion chromatography (SEC). A ApfA SEC; B VacJ SEC; Input: Proteins + cleaved tags before SEC; Fractions 1–2: Isolated fractions of purified ApfA and VacJ proteins after SEC. ApfA and VacJ proteins are indicated by black arrows. The size of selected bands of the protein marker in kilodaltons (kDa) is shown. ApfA theoretical molecular weight: 20 kDa; VacJ theoretical molecular weight: 27 kDa; Human thrombin molecular weight: 37 kDa.