Contribution of an alternative 16S rRNA helix to biogenesis of the 30S subunit of the ribosome

Disruption of hALT destabilizes the inactive state in vitro. (A,B) Comparing the rate of inactivation (A) or activation (B) of wild-type (gray circles) and mutant (red squares) 30S subunits. Reaction schemes (top) and representative primary data (inset) are shown. (NC) Nitrocellulose, (HB) Hybond-N⁺. Each plot shows fitted data for one replicate. Three independent replicates were performed, yielding the following rates (mean ± SEM): WT inactivation, 0.57 ± 0.13 min⁻¹; mutant inactivation, 0.65 ± 0.10 min⁻¹; WT activation, 0.09 ± 0.01 min⁻¹; mutant activation, 0.59 ± 0.05 min⁻¹. (C) Free energy diagram depicting inactive-to-active conversion for control (black) and mutant (red) subunits.