title: Exploring the capacity of trigger factor to function as a shield for ribosome bound polypeptide chains.
abstract: Ribosome-bound trigger factor (TF) is the first chaperone encountered by a nascent polypeptide chain in bacteria. TF has been proposed to form a cradle-shaped shield for nascent chains up to approximately 130 residues to fold in a protected environment upon exit from the ribosome. We report that nascent chains of luciferase up to 280 residues in length are relatively protected by TF against digestion by proteinase K. In contrast, nascent chains of the constitutively unstructured protein alpha-synuclein were not protected, although they were in close proximity to TF by crosslinking. Thus, TF is not a general shield for nascent chains. Protease protection appears to depend on a hydrophobic interaction of TF with nascent polypeptides.
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
authors.forename: Sladjana
authors.initials: S
authors.lastname: Tomic
authors.forename: Arthur E
authors.initials: AE
authors.lastname: Johnson
authors.forename: F Ulrich
authors.initials: FU
authors.lastname: Hartl
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Etchells
mesh_terms: D000818:Animals; D002474:Cell-Free System / Q000737:chemistry / Q000378:metabolism; D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D008156:Luciferases / Q000096:biosynthesis / Q000737:chemistry; D051379:Mice; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D014176:Protein Biosynthesis / Q000502:physiology*; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism*; D051844:alpha-Synuclein / Q000096:biosynthesis / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D029968:Escherichia coli Proteins; D010455:Peptides; D051844:alpha-Synuclein; D008156:Luciferases; D018833:Chaperonins; C403324:trigger factor, E coli; D019696:Peptidylprolyl Isomerase