TABLE 1.

Effects of hexoses (glucose, fructose, and galactose) and amino sugars on the expression of glmS, nagA, and nagB promoter fusions^a

Sugar(s)	PnagA::cat		PnagB::cat		PglmS::cat
	CAT sp act	FOR	CAT sp act	FOR	CAT sp act	FOR
GlcN	79.8 ± 7.3		813.6 ± 71		24.7 ± 1.0
GlcNAc	57.7 ± 6.7		464.0 ± 27		11.5 ± 1.6
Glucose	1.0 ± 0.2		3.0 ± 0.9		269.6 ± 5.4
Glucose and GlcN	2.3 ± 0.6	34.2	1.4 ± 0.8	590.3	10.01 ± 4.2	26.9
Glucose and GlcNAc	16.3 ± 0.7	3.5	330.1 ± 33	1.4	31.2 ± 1.4	8.6
Fructose	0.5 ± 0.3		9.0 ± 0.7		362.6 ± 6.1
Fructose and GlcN	37.0 ± 1.8	2.2	224.3 ± 37	3.6	17.8 ± 1.5	20.4
Fructose and GlcNAc	15.1 ± 0.5	3.8	90.5 ± 14	5.1	10.5 ± 5.0	34.5
Galactose	1.1 ± 0.2		6.8 ± 0.2		483.0 ± 40
Galactose and GlcN	58.6 ± 6.0	1.4	751.4 ± 15	1.1	23.03 ± 2.6	21.0
Galactose and GlcNAc	56.9 ± 1.2	1.0	492.6 ± 53	0.9	24.0 ± 1.6	20.1

^aAfter measuring the CAT activities (expressed as the average number of nanomoles per milligram of protein per minute ± standard deviation) in the background of UA159, the fold of repression (FOR) by a specific hexose (for nagA and nagB) was calculated as the ratio between activities from cells growing on one amino sugar alone and those on two sugars, and the fold of repression by an amino sugar (for glmS) is the ratio between activities from cells growing on one hexose and those on two sugars. Each carbohydrate was present at a concentration of 0.5%.