VapC6, a ribonucleolytic toxin regulates thermophilicity in the crenarchaeote Sulfolobus solfataricus

Characterization of VapC6_3′His activity and interaction with VapB6_3′His. (A) VapC6_3′His activity. S. solfataricus total RNA (4 μg) was treated at various temperatures with increasing amounts of VapC6_3′His. (Lane 1) No VapC6_3′His; (lanes 2–5) 0.75 μg, 2.25 μg, 3.75 μg, 7.5 μg VapC6_3′His; (lane 6) Ribonuclease A; (lane 7) VapC6 mock extract. (B) VapB6_3′His effect. VapB6_3′His effect on VapC6_3′His ribonuclease activity toward total Sso RNA was examined at 80°C . (Lane 1) Sso RNA (4 μg); (lane 2) VapC6_3′His (0.75μg); (lanes 3–6) VapB6_3′His and VapC6_3′His at ratios of 1:1, 5:1, 10:1 and 20:1; (lane 7) VapB6 mock extract and VapC6_3′His at 20:1; (lane 8) Ribonuclease A; (lane 9) VapB6_3′His; (lane 10) VapC6_3′His pretreated at 95°C.