title: A gram-negative characteristic segment in Escherichia coli DnaK is essential for the ATP-dependent cooperative function with the co-chaperones DnaJ and GrpE.
abstract: We describe importance of the characteristic segment in ATPase domain of DnaK chaperone which is present in all gram-negative bacteria but is absent in all gram-positive bacteria. In vitro studies, ATPase activity, luciferase-refolding activity, and surface plasmon resonance analyses, demonstrated that a segment-deletion mutant DnaKDelta74-96 became defective in the cooperation with the co-chaperones DnaJ and GrpE. In addition, in vivo complementation assay showed that expression of DnaKDelta74-96 could not rescue the viability of Escherichia coli DeltadnaK mutant at 43 degrees C. Consequently, we suggest evolutionary significance for this DnaK ATPase domain segment in gram-negative bacteria towards the DnaK chaperone system.
authors.affiliation: Laboratory of Microbial Technology, Division of Microbial Science and Technology, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Hakozaki, Fukuoka, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Sugimoto
authors.forename: Chihana
authors.initials: C
authors.lastname: Higashi
authors.forename: Kozue
authors.initials: K
authors.lastname: Saruwatari
authors.forename: Jiro
authors.initials: J
authors.lastname: Nakayama
authors.forename: Kenji
authors.initials: K
authors.lastname: Sonomoto
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology*; D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D019143:Evolution, Molecular; D017353:Gene Deletion; D005816:Genetic Complementation Test; D006090:Gram-Negative Bacteria / Q000235:genetics; D050956:HSP40 Heat-Shock Proteins / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D018832:Molecular Chaperones / Q000502:physiology; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; C489400:GrpE protein, E coli; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D050505:Mutant Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C063842:dnaK protein, E coli