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1.
FIG. 1.

FIG. 1. From: MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae .

Chromosomal-map positions of MtrR-regulated genes. The positions of MtrR-regulated genes in strain FA19 that were identified by the microarray analysis (Table 3) are shown on the circular map of the gonococcal chromosome (strain FA1090). MtrR-activated genes are shown in red, while MtrR-repressed genes are shown in green.

Jason P. Folster, et al. J Bacteriol. 2009 January;191(1):287-297.
2.
FIG. 4.

FIG. 4. From: MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae .

MtrR regulation of the RpoH-regulated grpE gene. Shown are the β-Gal-specific activities expressed in grpE-lacZ fusion strains JF11 (MtrR positive) and JF12 (MtrR negative) and the mtrR+ complemented strain JF13. The results are shown as average values (± standard deviations) from three independent assays. The differences between strains JF11 and JF12 and between JF12 and JF13 were significant (P < 0.001 and 0.003, respectively).

Jason P. Folster, et al. J Bacteriol. 2009 January;191(1):287-297.
3.
FIG. 5.

FIG. 5. From: MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae .

H2O2 induction of rpoH expression. Shown in the graph are the β-Gal-specific activities in rpoH-lacZ fusion strain JF8 after a 15-min exposure to 1 mM H2O2. The results are shown as average values (± standard deviations) from three independent assays; the difference was significant (P < 0.00001). The inset shows the changes in expression for mtrR, rpoH, and grpE when fusion strains were exposed to H2O2.

Jason P. Folster, et al. J Bacteriol. 2009 January;191(1):287-297.
4.
FIG. 6.

FIG. 6. From: MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae .

Identification of the MtrR-binding site within the rpoH promoter. The MtrR-binding site (see the nucleotide sequences in Fig. 2 and its legend) was identified by DNase I protection using increasing amounts of MtrR (0, 5, 10, and 20 μg) in assays that employed sense and antisense probes. The site of protection on each strand is shown by the vertical bar adjacent to the protected region. The nucleotide-sequencing reaction for each strand is shown (G, A, T, C) adjacent to the lanes with the protection reactions.

Jason P. Folster, et al. J Bacteriol. 2009 January;191(1):287-297.
5.
FIG. 3.

FIG. 3. From: MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae .

MtrR regulation of rpoH expression. (A) Levels of β-Gal activity (specific activity expressed as nanomoles of o-nitrophenyl-β-d-galactopyranoside hydrolyzed per mg of protein) in strains JF8 (like FA19, but rpoH-lacZ), JF9 (like JF1, but rpoH-lacZ), and JF10 (like JF6 [Table 1], but rpoH-lacZ). Complementation of the mtrR deletion mutation resulted in reduced rpoH expression. The results are shown as average values (± standard deviations) from three independent assays. The difference in β-Gal activities between strains JF8 and JF9 was significant (P < 0.001), as was that between JF9 and JF10 (P < 0.001). (B) MtrR repression of rpoH was independent of the 172-bp leader sequence upstream of rpoH, as shown by similar levels of β-Gal production between isogenic pairs (MtrR-positive strains JF8 and JF14 and MtrR-negative strains JF9 and JF15) with (strains JF8 and JF9) or without (JF14 and JF15) the 172-bp leader sequence. The differences in β-Gal activities between strains JF8 and JF14 and between JF9 and JF15 were not statistically significant.

Jason P. Folster, et al. J Bacteriol. 2009 January;191(1):287-297.
6.
FIG. 2.

FIG. 2. From: MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae .

Nucleotide sequence upstream of rpoH and identification of the MtrR-binding site. The nucleotide sequence of the DNA upstream of rpoH is shown with the 172-bp leader sequence indicated by the dashed lines; the first two codons encoding methionine (M) and asparagine (N) are also shown in boldface. The position of the transcriptional start point (8) is shown by the boldface A nucleotide downstream of the −10 sequence. The −10 and −35 sequences of the rpoH promoter identified previously (8) are shown with the −10 and −35 hexamers and are highlighted by a single line under the sequence. The 4-bp ribosome binding site (RBS) sequence is shown by an underline. The MtrR-binding site identified by DNase I protection (Fig. 6) is shown by the wide bars above the coding strand and below the noncoding strand. The boxed region shows a 15-nucleotide sequence on the coding strand (5′-GGC[-]CGTTTACATACA-3′) that is 73.3% identical (the identical nucleotides are boldface in above sequence) to the MtrR-binding sequence (5′-GGCACGTTAGCACATA-3′) upstream of mtrCDE on the noncoding strand (12); the hyphen in the sequence above represents a single-nucleotide gap in the rpoH sequence compared to the mtrCDE bound by MtrR.

Jason P. Folster, et al. J Bacteriol. 2009 January;191(1):287-297.
7.
FIG. 7.

FIG. 7. From: MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae .

Inducible production of MtrR represses rpoH expression and modulates antimicrobial susceptibility levels in gonococci. (A and B) Strain JF7 was grown in the presence or absence of 1 mM IPTG as described in Materials and Methods, and cell lysates before induction (0 Hour) or after 1 h of incubation in the absence (−) or presence (+) of IPTG were solubilized and subjected to SDS-PAGE using a 12.5% (wt/vol) SDS-PAGE gel with the separated proteins stained by Coomassie brilliant blue (A); the positions of the molecular mass markers are shown on the left of the gel, and the approximate positions of MtrR as determined by immunoblotting with detection using anti-MtrR antiserum (B) are shown. (C) Specific activity values for β-Gal levels in the control (−IPTG) and induced (+IPTG) cultures. The results are shown as average values (± standard deviations) from three independent assays. The difference was significant (P = 0.0012). (D) The efficiencies of plating of the control and IPTG-induced cultures on GCB agar with or without 0.5 μg/ml of Ery are shown. (E) The H2O2 susceptibilities of the control and IPTG-induced cultures were assessed by a disk diffusion assay, and the difference in growth inhibition between the cultures was significant (P < 0.001).

Jason P. Folster, et al. J Bacteriol. 2009 January;191(1):287-297.

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