title: The ABC-F protein EttA gates ribosome entry into the translation elongation cycle.
abstract: ABC-F proteins have evaded functional characterization even though they compose one of the most widely distributed branches of the ATP-binding cassette (ABC) superfamily. Herein, we demonstrate that YjjK, the most prevalent eubacterial ABC-F protein, gates ribosome entry into the translation elongation cycle through a nucleotide-dependent interaction sensitive to ATP/ADP ratio. Accordingly, we rename this protein energy-dependent translational throttle A (EttA). We determined the crystal structure of Escherichia coli EttA and used it to design mutants for biochemical studies including enzymological assays of the initial steps of protein synthesis. These studies suggest that EttA may regulate protein synthesis in energy-depleted cells, which have a low ATP/ADP ratio. Consistently with this inference, EttA-deleted cells exhibit a severe fitness defect in long-term stationary phase. These studies demonstrate that an ABC-F protein regulates protein synthesis via a new mechanism sensitive to cellular energy status.
authors.affiliation: 1] Department of Biological Sciences, Columbia University, New York, New York, USA. [2] Northeast Structural Genomics Consortium, Columbia University, New York, New York, USA.
authors.forename: Grégory
authors.initials: G
authors.lastname: Boël
authors.affiliation: 1] Department of Biological Sciences, Columbia University, New York, New York, USA. [2].
authors.forename: Paul C
authors.initials: PC
authors.lastname: Smith
authors.affiliation: Department of Chemistry, Columbia University, New York, New York, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Ning
authors.affiliation: 1] Department of Chemistry, Columbia University, New York, New York, USA. [2] Integrated Program in Cellular, Molecular and Biomedical Studies, Columbia University, Medical Center, New York, New York, USA. [3].
authors.forename: Michael T
authors.initials: MT
authors.lastname: Englander
authors.affiliation: Department of Biological Sciences, Columbia University, New York, New York, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: 1] Department of Biochemistry, Columbia University Medical Center, New York, New York, USA. [2] Howard Hughes Medical Institute, Columbia University Medical Center, New York, New York, USA.
authors.forename: Yaser
authors.initials: Y
authors.lastname: Hashem
authors.affiliation: Department of Biological Sciences, Columbia University, New York, New York, USA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Testa
authors.affiliation: 1] Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada. [2].
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fischer
authors.affiliation: Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Wieden
authors.affiliation: 1] Department of Biological Sciences, Columbia University, New York, New York, USA. [2] Department of Biochemistry, Columbia University Medical Center, New York, New York, USA. [3] Howard Hughes Medical Institute, Columbia University Medical Center, New York, New York, USA.
authors.forename: Joachim
authors.initials: J
authors.lastname: Frank
authors.affiliation: Department of Chemistry, Columbia University, New York, New York, USA.
authors.forename: Ruben L
authors.initials: RL
authors.lastname: Gonzalez
authors.affiliation: 1] Department of Biological Sciences, Columbia University, New York, New York, USA. [2] Northeast Structural Genomics Consortium, Columbia University, New York, New York, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Hunt
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D018360:Crystallography, X-Ray; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D008958:Models, Molecular; D010441:Peptide Chain Elongation, Translational; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D018528:ATP-Binding Cassette Transporters; D029968:Escherichia coli Proteins; C587789:EttA protein, E coli