Figure 3.
Effect of cobalamins on the amount of btuB primer extension inhibition products. Binding reactions were carried out in the presence of the indicated concentrations of Ado-Cbl (circles), methyl-Cbl (squares), and CN-Cbl (diamonds), with 200 nM 30S subunits and 1 μM tRNAFMet. (A) Ribosome binding to the translation initiation site to generate fragment T256. (B) Formation of cobalamin-dependent A202 product. (C) Data from A (open symbols) and B (closed symbols) are plotted as the percent of the maximal effect to compare the effect of Ado-Cbl (circles) and methyl-Cbl (squares) on inhibition of ribosome binding (open symbols) and formation of fragment A202 (closed symbols) vs. cobalamin concentration.