TABLE 2.

Relative mRNA levels of a subset of selected genes involved in sulfur metabolism in response to the knockout of tetH and tetH overexpression^a

Gene	Locus	Gene description	Log2 ratio medianb
			9K-S0		9K-K2S4O6		9K-FeSO4
			A	B	A	B	A	B
tetH	AFE_0029	Tetrathionate hydrolase	—*	3*	—	12.7*	—	2.3*
doxD2	AFE_0044	DoxD-like family protein	−1.8*	2.6*	—	10.4*	−1.6*	1.4
doxD1	AFE_0048	DoxD-like family protein	−0.6	0.9	—	1.5*	−0.9	0.3
sqr	AFE_0267	Sulfide quinone reductase, putative	−1.4	2.3*	—	1.3	−0.6	−1.2
sdo	AFE_0269	Metallo-beta-lactamase family protein	1.2	−0.2	—	−0.5	−1.1	−0.4
sat	AFE_0539	Sulfate adenylyltransferase, putative adenylylsulfate kinase	1.3	−0.6	—	1.6*	−0.2	−0.6
sqr	AFE_1792	Sulfide quinone reductase, putative	−1.0	1.9*	—	0.9	−0.5	−0.7
hdrB	AFE_2554	Heterodisulfide reductase subunit B, homolog	−1.1	1.7*	—	1.1	−1.1	−0.9
rhd	AFE_2558	Rhodanase-like domain protein	−1.4	1.5*	—	1.5*	−0.9	−0.5

^aDetermined by qRT-PCR analysis against the wild-type A. ferrooxidans ATCC 23270 cultivated in different media.

^bA, the ΔtetH mutant of A. ferrooxidans; B, the tetH overexpression strain of A. ferrooxidans; —, no mRNA of the relevant genes was detected in the ΔtetH mutant. Genes for which the log₂ ratio of the median was larger than |1.5| (corresponding to genes induced more than 2.8-fold) are considered differentially expressed (indicated with *). The locus of a relevant gene and its description are those of the GenBank genome annotation of NC_011761. The negative numbers represent downregulation, while positive numbers represent upregulation. The qRT-PCRs were performed in triplicate, with at least three independent biological replicates.