Figure 4

EMSA showing binding of hfq to the rsmY sequence. (A) Purified Hfq protein. (B) The 1-nM biotin-labeled DNA probe was incubated with purified Hfq protein in 20 μL binding buffer, and the Hfq-DNA complexes and free DNAs were cross-linked to the membrane by a 320-nm UV-light cross-linking instrument. Biotin-labeled bands were detected by chemiluminescent nucleic acid detection module. (C) Hfq protein directly bound to the rsmY sequence, but did not do so to rsmA, rsmE, and rsmZ sequences following increases in free rsmY. The different ratios of free rsmY to biotin-labeled rsmY used were 1:1, 50:1, 100:1, and 150:1 in groups 1 through 4.