Figure 1.

Phenotypic comparison of protein kinase mutants with strains carrying mutations in the xprG, hxkC and hxkD genes. Colony morphology (A) and radial growth rate (B) on media containing bovine serum albumin (BSA), ammonium tartrate (NH₄), hypoxanthine (hypox) or aspartic acid (asp) as a nitrogen source [N] or BSA as a carbon source [C]. The full genotypes for the wild type (WT) (MH2), imeBΔ (MK598), mpkCΔ (MK609), phoBΔ (607), phoAΔ (MK552), xprGΔ (MK422), xprG1 (MK85), hxkCΔ (MK489) and hxkDΔ (MK490) strains are given in Table 1. Radial growth rate was measured between 20 and 44 hr after inoculation. For each strain, the average growth rate and standard error for three colonies grown on three separate plates are shown. An unpaired t-test was used to analyze the data. Values that differed significantly from the value for the WT strain are indicated with asterisks (* P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001).