Figure 3.

Gel-shift assay showing HutP–RNA complexes. All reactions were carried out in binding buffer (15 mM HEPES pH 7.5, 30 mM NaCl) with 20 nM of RNA (labeled RNA 10⁴ c.p.m.) containing 10 mM of l-his and Mg²⁺ ion. To this reaction mixture, various amount of purified HutP protein (to a final concentration of 50–800 nM) were added, and after an incubated for 15 min, the reactions were fractionated by 8% native PAGE. The positions of the free and complex RNA (protein to RNA, 1:1 ratio) are indicated by an arrow and an open arrowhead, respectively. The 21-mer RNA complex (protein to RNA, 1:2 ratio) is indicated by a filled arrowhead.