E. coli proteins detected as a function of mRNA signal intensity. (A) The number of proteins detected in the short (hatched bars) or total (open bars) lists or the number of mRNAs (filled bars) detected for protein-coding genes on Affymetrix arrays was plotted as a function of mRNA signal intensity. (A Inset) An expansion of the data for proteins/mRNAs with signal intensities (×103) ≤3. (B) To get the x axis, the 2,826 protein-coding genes expressed on Affymetrix arrays were first sorted from lowest to highest mRNA signal intensity. They were then divided into 10 equal classes (283 each). Class 1 contained the 10% of genes with the lowest intensities, and so on. The proportion (percent) of the 283 proteins in each class that was detected was plotted on the y axis (short list or total list). (C) The x axis is as for B. The proportion (percent) of all proteins in a list (short or total) that corresponded to genes in each class was plotted on the y axis. The ranges of mRNA signal intensities for classes 1–10 were as follows: 1, 51–227; 2, 227–327; 3, 327–446; 4, 447–625; 5, 625–878; 6, 879–1,179; 7, 1,181–1,781; 8, 1,782–2,828; 9, 2,830–5,467; 10, 5,468–58,952.