Fig. 6.

Lrp binding with the promoters of various genes and the mRNA levels of these genes in bacteria incubated in mouse serum. a Binding of biotin-labeled DNA probe with increasing amounts of Lrp (lanes 2–4) was competed with excess amount of unlabeled DNA (lane 5). The effect of leucine on binding of Lrp with DNA probe was also tested (lanes 6 and 7). b Total RNA was extracted from the bacteria cultured in 80% mouse serum for 2 h, and the mRNA level of each gene was estimated by qRT-PCR. n = 3. YJ016: wild-type strain; YH01: Δlrp mutant. 23S rRNA was used as internal control. Arrow head: DNA probe; Arrow: shifted band corresponding to Lrp-bound DNA probe. ***: P < 0.001 analyzed by paired Student’s t-test