Fig. 6.

Stimulation of the GTPase activity of SsoHflX by ribosomal subunits in the presence of 250 μM GTP. (A) Effect of partially purified ribosomes on SsoHflX GTPase activity. GTPase activity of SsoHflX was measured in the absence of ribosomes (1) or with 1 μM ribosomes purified by 6-h sucrose cushion centrifugation at 100 mM NH₄Cl (2) or 500 mM NH₄Cl (3). (B) Stimulation of GTPase activity of SsoHflX by isolated ribosomal subunit GTPase activity was measured in the absence of ribosomal subunits (1) or the presence of 1 μM 50S (2), 0.6 μM 30S (3), or a mixture of 50S and 30S (4) ribosomal subunits. (C) Stimulation of GTPase activity of SsoHflX by increasing amounts of highly purified 50S ribosomal subunits after 13 h of sucrose cushion centrifugation at 500 mM NH₄Cl. Error bars show 1 standard deviation.