This Article Full Text Full Text (PDF) Other Versions of this Article: JB.01686-06v1 189/8/3237    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Dethlefsen, L. Articles by Schmidt, T. M. Search for Related Content PubMed PubMed Citation Articles by Dethlefsen, L. Articles by Schmidt, T. M.

Performance of the Translational Apparatus Varies with the Ecological Strategies of Bacteria

Les Dethlefsen and Thomas M. Schmidt^*

Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824

Received 31 October 2006/ Accepted 23 January 2007

Protein synthesis is the predominant activity of growing bacteria; the protein synthesis system accounts for more than one-half the cell's dry mass and consumes most of the cell's energy during rapid growth. Translation has been studied extensively using model organisms, and the translational apparatus is qualitatively similar in terms of structure and function across all known forms of life. However, little is known about variation between organisms in translational performance. Using measurements of macromolecular content in a phylogenetically diverse collection of bacteria with contrasting ecological strategies, we found that the translational power (the rate of protein synthesis normalized to the mass of the protein synthesis system) is three- to fourfold higher among bacteria that respond rapidly to nutrient availability than among bacteria that respond slowly. An analysis of codon use in completely sequenced bacterial genomes confirmed that the selective forces acting on translation vary with the ecological strategy. We propose that differences in translational power result from ecologically based variation among microbes in the relative importance of two competing benefits: reducing the biomass invested in the protein synthesis system and reducing the energetic expense of protein synthesis.

Published ahead of print on 2 February 2007.

Present address: Department of Microbiology and Immunology, Stanford University, Palo Alto, CA 94304.