Table 1.
Strains and plasmids used in this study.
Fig 1.
Genetic organization of BAS0228 (hmgA) region.
Numbers above specify size of intergenic regions. Predicted transcriptional terminator indicated downstream of hmgA.
Fig 2.
Characteristics of ΔhmgA mutant strain.
A. Pigment production in strains grown on LB-agar for 48 hours at 37°C. Top, AW-A127 (ΔhmgA); Bottom left, parental 34F2; Bottom right, AW-A130 (ΔhmgB). B. Pigment production in supernatants of strains grown in LB for 72 hours at 37°C. Left, 34F2; Center, AW-A127 (ΔhmgA); Right, AW-A130 (ΔhmgB). C. Optical spectra of AW-A127 (ΔhmgA) supernatant following subtraction of 34F2 supernatant spectra. D. Cell growth of parental and mutant strains grown in LB at 37°C. -■- 34F2; -□- AW-A127 (ΔhmgA).
Fig 3.
Complementation analysis of ΔhmgA mutant strain.
A. Pigment production in strains grown on LB-agar for 48 hours at 37°C. B. Pigment production in supernatants of strains grown in LB for 72 hours at 37°C. For both: 1. 34F2 + pAW285 (empty vector); 2. 34F2 + pAW444 (hmgA); 3. AW-A127 (ΔhmgA) + pAW285 (empty vector); 4. AW-A127 (ΔhmgA) + pAW444 (hmgA).
Fig 4.
Growth and pigment production in defined medium.
A. Cell growth of parental and mutant strains grown in R-Bic medium at 37°C. -■- 34F2 in R-bic; -◆- AW-A127 (ΔhmgA) in R-bic; -▲- 34F2 in R-bic without L-tryptophan, L-phenylalanine, or L-tyrosine; -●- AW-A127 in R-bic without L-tryptophan, L-phenylalanine, or L-tyrosine. B. Pigment production in 34F2 supernatants. C. Pigment production in AW-A127 supernatants. 1, R-bic without L-tryptophan, L-phenylalanine, or L-tyrosine; 2, R-bic without L-tryptophan or L-phenylalanine; 3, R-bic without L-tryptophan or L-tyrosine; 4, R-bic without L-phenylalanine or L-tyrosine.
Fig 5.
Pigment production in cell-free extracts.
Cell-free extracts from cells grown in LB at 37°C for 6 hours. Amino acids then added to cell-free extracts, as indicated, and incubated for an additional 24 hours at 37°C. 1, 34F2, no added amino acids; 2, 34F2 with L-tyrosine; 3, 34F2 with L-phenylalanine; 4, 34F2 with L-tryptophan; 5, AW-A127 (ΔhmgA), no added amino acids; 6, AW-A127 with L-tyrosine; 7, AW-A127 with L-phenylalanine; 8, AW-A127 with L-tryptophan.
Fig 6.
A. UV protection. Survival of 34F2 (blue) or AW-A127 (ΔhmgA) (red) following irradiation with UV at 302 nm as indicated. Data was obtained from 3 independent cultures and error bars represent standard deviation from the mean. Two tailed unpaired t test indicate P value of P<0.0001 between 34F2 and AW-A127 at both levels of UV exposure. B. UV protection of complemented strains. Survival of 34F2+pAW285 (blue), AW-A127+pAW285 (red), 34F2+pAW444 (green), and AW-A127+pAW444 (purple) following irradiation with UV at 302 nm as indicated. Data was obtained from 3 independent cultures and error bars represent standard deviation from the mean. C. H2O2 survival. Survival of 34F2 cells in 50mM H2O2 when resuspended in supernatants from 34F2 or AW-A127 (ΔhmgA) cultures. Data was obtained from 3 independent cultures and error bars represent standard deviation from the mean.
Fig 7.
Virulence gene expression in 34F2 and ΔhmgA strains.
β-galactosidase activity in virulence gene reporter strains grown in LB supplemented with kanamycin at 37°C. -■- 34F2 pagA-lacZ; -□- AW-A127 pagA-lacZ -◆- 34F2 atxA-lacZ; -◇- AW-A127 atxA-lacZ;.