Figure 1.

Average mutation rates (with error bars depicting the standard deviation) of the 27S (blue) and 50S (red) Ψ modifications. (A) Ψ isomerizations at positions 957, 2461, 2508, 2584, 2608, and 2609, which occur at the early stages of large subunit ribosome assembly, have similar levels of average mutation rates in the 27S and 50S. (B) Ψ isomerizations, which occur after the 27S intermediate accumulates in the cell, are U nucleotides 1919 and 1921. The U nucleotides 1919 and 1921 to Ψ isomerizations and methylation of Ψ 1919 occur at the intermediate and/or late stage of large subunit ribosome assembly. As explained in the Results and Discussion, we are showing the background-uncorrected average mutation rates for Ψ 1919*. All the average mutation rate and the standard deviation values for the wild-type 50S large subunit depicted in this figure are from our previous publication.²⁰ The averages and standard deviations depicted in this figure were calculated using eqs 2 and 3.