Identification of HemW protein interaction partner using a bacterial two-hybrid system. Shown are the resulting β-galactosidase activities in Miller units (MU) for the testing of the following bait-prey pairs: HemW-BfrA with pUT18C-hemW/pKT25-bfrA (1), HemW-HemH with pUT18C-hemW/pKT25-hemH (2), HemW-KatA with pUT18C-hemW/pKT25-katA (3), HemW-BfrB with pKT25-hemW/pUT18C-bfrB (4), HemW-NarI with pUT18C-hemW/pKNT25-narI (5), and HemH-BfrB with pUT18C-hemH/pKT25-bfrB (6). pKNT25/pUT18 served as a negative control (7), and pKT25-zip/pUT18C-zip served as a positive control (8). Error bars represent S.D.