title: Protein folding. Translational tuning optimizes nascent protein folding in cells.
abstract: In cells, biosynthetic machinery coordinates protein synthesis and folding to optimize efficiency and minimize off-pathway outcomes. However, it has been difficult to delineate experimentally the mechanisms responsible. Using fluorescence resonance energy transfer, we studied cotranslational folding of the first nucleotide-binding domain from the cystic fibrosis transmembrane conductance regulator. During synthesis, folding occurred discretely via sequential compaction of N-terminal, α-helical, and α/β-core subdomains. Moreover, the timing of these events was critical; premature α-subdomain folding prevented subsequent core formation. This process was facilitated by modulating intrinsic folding propensity in three distinct ways: delaying α-subdomain compaction, facilitating β-strand intercalation, and optimizing translation kinetics via codon usage. Thus, de novo folding is translationally tuned by an integrated cellular response that shapes the cotranslational folding landscape at critical stages of synthesis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health and Science University (OHSU), Portland, OR 97239, USA.
authors.forename: Soo Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health and Science University (OHSU), Portland, OR 97239, USA.
authors.forename: Jae Seok
authors.initials: JS
authors.lastname: Yoon
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health and Science University (OHSU), Portland, OR 97239, USA.
authors.forename: Hideki
authors.initials: H
authors.lastname: Shishido
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health and Science University (OHSU), Portland, OR 97239, USA.
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health and Science University (OHSU), Portland, OR 97239, USA.
authors.forename: LeeAnn A
authors.initials: LA
authors.lastname: Rooney
authors.affiliation: Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77550-0620, USA. Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550-0620, USA.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Barral
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health and Science University (OHSU), Portland, OR 97239, USA. Cystic Fibrosis Foundation Therapeutics, Bethesda, MD 20814, USA. skachw@ohsu.edu.
authors.forename: William R
authors.initials: WR
authors.lastname: Skach
mesh_terms: D000595:Amino Acid Sequence; D003062:Codon / Q000737:chemistry / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010441:Peptide Chain Elongation, Translational; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism
chemical_list: D003062:Codon; D019005:Cystic Fibrosis Transmembrane Conductance Regulator