Table 5. Downregulation of mRNA levels for “late” flagellar genes (flagellar filament, motor stator, and coregulated chemotaxis genes) in O157:H7 cells treated with 0.8% bile salts relative to control.

Gene	Protein function	Fold change	p-value
Class 2/Class 3 (middle & late) genes - fliDST operon
fliD	flagellar capping protein	.47	< .001
fliS	flagellar protein, potentiates polymerization	.47	< .001
fliT	flagellar biosynthesis protein	.43	< .001
Class 2/Class 3 (middle & late) genes – flgKL operon
flgK	flagellar hook-filament junction protein	.63	.024
flgL	flagellar hook-filament junction protein	.53	< .001
Class 3 (late) gene – fliC
fliC	Flagellin	.53	< .001
Class 3 (late) genes – tar-tap-cheZYBR operon
tar	methyl-accepting chemotaxis protein; sensor	.51	< .001
tap	chemotaxis for dipeptides & pyrimidines	.45	< .001
cheR	chemotaxis regulator, methyltransferase	.44	< .001
cheB	chemotaxis-specific methylesterase	.48	< .001
cheY	chemotaxis regulator, signaling to flagellar motor	.57	.001
cheZ	chemotaxis regulator, protein phosphatase for CheY	.55	< .001
Class 3 (late) genes – motAB-cheAW operon
motA	stator, proton conductor component of flagella motor	.51	< .001
motB	stator, protein that enables flagellar motor rotation	.49	< .001
cheA	chemotaxis response regulator	.41	< .001
cheW	purine-binding chemotaxis protein	.45	< .001
Class 3 (late) genes -tsr & aer
tsr	Methyl-accepting chemotaxis protein, serine sensor	.40	< .001
aer	aerotaxis sensor receptor, flavoprotein	.27	< .001

Calculations of “fold change” are based on triplicate culture/microarray experiments for each treatment.