FIG. 4.

Growth of P. gingivalis hmuR mutant strains in media containing human serum supplemented with different concentrations of hemin. P. gingivalis wild-type strain A7436 and the hmuR site-directed mutant strains were depleted of heme and inoculated into BM alone (A) or BM containing 10% human serum supplemented with 0 (B), 1.5 μM (C), or 50 μM (D) of hemin for growth analysis as described in Materials and Methods. The free and complexed forms of heme in different media were examined by native gel analysis and detected by UV light (E). ⧫, A7436, P. gingivalis wild-type strain; ▪, WS1, P. gingivalis hmuR::ermF; ▴, WS21, P. gingivalis hmuR^H95A; •, WS22, P. gingivalis hmuR^H434A; ×, WS23, P. gingivalis hmuR^H95A,H434A; ○, WS24, P. gingivalis hmuR^{YRAP420-423YAAA}; ⋄, WS25, P. gingivalis hmuR^{NPDL442-445NAAA}; □, WS26, P. gingivalis ermF control.