FIG 4 .

DNA relaxation reduces motility through an alteration of flagellar transcription and protein expression. (A) RT-PCR of flagellar and topoisomerase genes from strain 81-176 and strain NCTC 11168 grown with or without novobiocin (0, 10, or 20 µg/ml). (B) qPCR of flaA and flgR confirms the RT-PCR results. Changes in gene expression for each gene are shown in comparison to the resting levels in strain NCTC 11168 grown without novobiocin. Changes in gene expression in strain NCTC 11168 in the presence and absence of novobiocin are noted as being significant if they had a P value of <0.05 (*), very significant at a P value of <0.01 (**), or not significant (NS). Error bars show standard deviations. (C) Western blots of protein lysates of strain NCTC 11168 grown with increasing concentrations of novobiocin using flagellin antiserum, FlgR antiserum, and FlgS antiserum.