Table 1The Composition of a Typical E. coli Cell

Substance% of massMW# of copies# of kinds
Water70184 × 1010 1
Inorganic ions and small molecules of all other kinds7˜ 1455 × 108 750
DNA13 × 109 41
RNA6
16S rRNA0.5 × 106 30,0007
23S rRNA1.0 × 106 30,0007
5S rRNA4.0 × 10430,0007
tRNA2.5 × 104 300,00086
mRNA˜1.0 × 106 ˜1,000˜1,000
Proteins15˜30,0005 × 106 4,288

SOURCE: Adapted from Watson (1965); data from Blattner et el. (1997).

From: A Biophysical Chemist's Thoughts on Cell Size

Cover of Size Limits of Very Small Microorganisms
Size Limits of Very Small Microorganisms: Proceedings of a Workshop.
National Research Council (US) Steering Group for the Workshop on Size Limits of Very Small Microorganisms.
Washington (DC): National Academies Press (US); 1999.
Copyright 1999 by the National Academy of Sciences. All rights reserved.

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