FIG. 3.
Confirmation of the direct interaction between G1ORF67 and S. aureus σSA. (A) Far-Western analysis demonstrates the direct interaction of σSA with G1ORF67. Increasing amounts of purified His-tagged G1ORF67 (100 ng to 2 μg, lanes 1 to 5) or 2 μg of 77ORF104 (lane 6) were separated by SDS-PAGE, immobilized onto a nitrocellulose membrane, and probed with 32P-labeled σSA. Protein standards (masses in kDa) are indicated on the right. (B) Dose-response study of the interaction between G1ORF67 and σSA by TR-FRET as described in Materials and Methods. Untagged G1ORF67 or 77ORF104 polypeptides were used as competitors. Error bars show standard deviations.