title: Reduction of translating ribosomes enables Escherichia coli to maintain elongation rates during slow growth.
abstract: Bacteria growing under different conditions experience a broad range of demand on the rate of protein synthesis, which profoundly affects cellular resource allocation. During fast growth, protein synthesis has long been known to be modulated by adjusting the ribosome content, with the vast majority of ribosomes engaged at a near-maximal rate of elongation. Here, we systematically characterize protein synthesis by Escherichia coli, focusing on slow-growth conditions. We establish that the translational elongation rate decreases as growth slows, exhibiting a Michaelis-Menten dependence on the abundance of the cellular translational apparatus. However, an appreciable elongation rate is maintained even towards zero growth, including the stationary phase. This maintenance, critical for timely protein synthesis in harsh environments, is accompanied by a drastic reduction in the fraction of active ribosomes. Interestingly, well-known antibiotics such as chloramphenicol also cause a substantial reduction in the pool of active ribosomes, instead of slowing down translational elongation as commonly thought.
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, California 92093-0374, USA.|State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Xiongfeng
authors.initials: X
authors.lastname: Dai
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, California 92093-0374, USA.|State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Manlu
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, California 92093-0374, USA.
authors.forename: Mya
authors.initials: M
authors.lastname: Warren
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, California 92093-0374, USA.|Department of Microbiology and Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Rohan
authors.initials: R
authors.lastname: Balakrishnan
authors.affiliation: Department of Integrative Structural and Computational Biology, Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: Vadim
authors.initials: V
authors.lastname: Patsalo
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, California 92093-0374, USA.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okano
authors.affiliation: Department of Integrative Structural and Computational Biology, Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Williamson
authors.affiliation: Department of Microbiology and Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Kurt
authors.initials: K
authors.lastname: Fredrick
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Wang
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, California 92093-0374, USA.
authors.forename: Terence
authors.identifier: http://orcid.org/0000-0003-1837-6842
authors.initials: T
authors.lastname: Hwa
mesh_terms: D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D011500:Protein Synthesis Inhibitors