title: Performance of the translational apparatus varies with the ecological strategies of bacteria.
abstract: 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.
authors.affiliation: Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824-4320, USA.
authors.forename: Les
authors.initials: L
authors.lastname: Dethlefsen
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Schmidt
mesh_terms: D000222:Adaptation, Physiological; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000096:biosynthesis*; D003062:Codon / Q000235:genetics; D017753:Ecosystem; D004734:Energy Metabolism; D005798:Genes, Bacterial; D014644:Genetic Variation; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012988:Soil Microbiology; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D003062:Codon