Fig 3. Epistasis analysis indicates MgrA acts downstream of ArlRS.

LAC WT, arlRS, and mgrA mutants contained either the empty vector or plasmids for constitutive expression of arlRS or mgrA. (A) Clumping ability was measured after two hours of incubation with human plasma, and results from three separate experiments were averaged. (B) Dot blot showing Ebh protein levels in 2-fold dilutions of culture supernatants from overnight cultures. Strains were identical to those used in Fig 3A except that they lacked spa, to prevent non-specific antibody binding.