Temperature effects on RNA-binding

Since P. furiosus is an extreme thermophilious archaea that can survive at about 100$\circ$ C, its gene expression may also be controlled by temperature. We checked the PF1684 protein RNA-binding activity under different temperature, and found that the RNA-binding activity is relied on the temperature (Figure 4). When the temperature was raised from 0$\circ$ C to 75$\circ$ C, the binding activity became stronger. But when the temperature was 94$\circ$ C, the binding activity reduced to a level lower than that of 0$\circ$ C. We are surprised to find an interesting phenomenon that when the binding activity is strong the bottom band of the probe is thick while when the binding activity is week at 94$\circ$ C the bottom band is lighter. We think this RNA-binding activity may be linked to some nuclease activity. This RNA-binding activity was found not subject to regulation by ATP.

Figure 4: RNA-binding activity of purified PF1684 protein under different temperatures and ATP concentrations

Arrows and "Free" are the same as in Figure 3. Stars are either the oligo RNA degradation product or the oligo RNA with changed structure, or the mixture of both.