Table 2.

Genes most affected by the overexpression of yehT^a

Gene	b-no.	rFb		Log2 ratioc	Pd	Function	Transcriptional regulation by YehTe
		YehT	KdpE
yjiY	b4354	9,170	50	7.6	≤10−3	Predicted inner membrane protein	↑
cspI	b1552	300	2,480	−3.0	0.01	Cold shock-like protein CspI	↓
yhjX	b3547	80	3,120	−5.3	≤10−3	Uncharacterized member of the major facilitator superfamily of transporters	↓
ypjB	b2649	20	1,790	−8.3	≤10−3	Hypothetical protein	↓

^aGene names, b-numbers, and gene product function are adopted from http://www.ecocyc.org (32) and the Affymetrix Expression Analysis Sequence Information Database (14).

^brF, relative fluorescence (arbitrary units).

^cLog₂ ratios of transcript levels for the yehT and kdpE overexpression strains, calculated from the ratio of the mean fluorescence intensity of the respective transcript in the yehT-overexpressing strain to that in the kdpE overexpression strain. A negative value indicates a decrease, and a positive value indicates an increase, in the transcription level upon YehT overproduction over that seen with KdpE overproduction.

^dSignificance (by the t test) of single rF values.

^eEffect of YehT overproduction on the transcript levels of the respective genes in E. coli MG2/pBAD24-yehT compared to control cells (E. coli MG2/pBAD24), as determined by Northern blot analysis. YehT-dependent induction (↑) or repression (↓) of the gene is indicated (see Fig. 2A).