Figure 3: Ribosome binding on h4 mRNAs.
From: Ribosomal 18S rRNA base pairs with mRNA during eukaryotic translation initiation
(a) Histogram showing 40S subunit binding on h4 mRNAs. Binding was studied on sucrose gradient with radiolabelled m7G-capped h4 mRNA. Samples were separated on 7–47% sucrose gradients, and complexes with 40S particles were counted in Cerenkov mode. Binding values were normalized to wild-type h4 binding with rabbit 40S particles. Values represent the average of three technical replicates. Errors bars representing the variability of data are shown. (b) Secondary structure of the 142 first nucleotides of murine histone h4 mRNA. The structure contains three helices connected by a TWJ followed by a stem-loop structure. The initiation codon is boxed. The black star indicates the location of the +17 ribosome toe-print. Partial helix 16 (h16) from yeast and mammalian (rabbit, human and mouse) are drawn in blue; nts numbering corresponds to rabbit sequence (rabbit 540=yeast 452). Mutated h4 mRNAs tested with 40S subunits from yeast are shown in the grey insets.
