Antifolding Activity of the SecB Chaperone Is Essential for Secretion of HasA, a Quickly Folding ABC Pathway Substrate
| Autor: | Christophe Bodenreider, Guillaume Sapriel, Philippe Delepelaire, Alain Chaffotte, Nicolas Wolff |
|---|---|
| Přispěvatelé: | Résonance Magnétique Nucléaire des Biomolécules, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Membranes bactériennes, Repliement et Modélisation des Protéines, We thank C. Wandersman for helpful discussions and critical reading of the manuscript and J. M. Betton for gift of the SecB overproducing plasmid., Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2003 |
| Předmět: |
Protein Folding
Time Factors [SDV]Life Sciences [q-bio] MESH: Serratia marcescens / metabolism Mutant MESH: Protein Structure Secondary MESH: Guanidine / chemistry medicine.disease_cause Biochemistry Protein Structure Secondary MESH: Circular Dichroism MESH: Dose-Response Relationship Drug MESH: Protein Structure Tertiary Adenosine Triphosphate Denaturation (biochemistry) Serratia marcescens 0303 health sciences MESH: Kinetics biology Circular Dichroism 030302 biochemistry & molecular biology MESH: Bacterial Proteins / metabolism Temperature MESH: Adenosine Triphosphate / metabolism MESH: Temperature [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry Molecular Biology/Biophysics MESH: Carrier Proteins / metabolism MESH: Escherichia coli / metabolism Plasmids Protein Binding MESH: Mutation Ultraviolet Rays MESH: Protein Folding MESH: Plasmids / metabolism 03 medical and health sciences Bacterial Proteins MESH: Membrane Proteins / metabolism Escherichia coli medicine MESH: Protein Binding [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology Secretion MESH: Hydrogen Bonding Molecular Biology Guanidine 030304 developmental biology Models Statistical Dose-Response Relationship Drug MESH: Time Factors Tryptophan Membrane Proteins Hydrogen Bonding Cell Biology biology.organism_classification MESH: Bacterial Proteins / chemistry Protein tertiary structure Protein Structure Tertiary Kinetics Chaperone (protein) Mutation biology.protein MESH: Ultraviolet Rays Carrier Proteins MESH: Models Statistical |
| Zdroj: | Journal of Biological Chemistry Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology, 2003, 278 (40), pp.38247-38253. ⟨10.1074/jbc.M302322200⟩ Journal of Biological Chemistry, 2003, 278 (40), pp.38247-38253. ⟨10.1074/jbc.M302322200⟩ |
| ISSN: | 0021-9258 1083-351X |
| Popis: | International audience; We have previously shown that SecB, the ATP-independent chaperone of the Sec pathway, is required for the secretion of the HasA hemophore from Serratia marcescens via its type I secretion pathway, both in the reconstituted system in Escherichia coli and in the original host. The refolding of apo-HasA after denaturation with guanidine HCl was followed by stopped-flow measurements of fluorescence of its single tryptophan, both in the absence and presence of SecB. In the absence of SecB, HasA folds very quickly with one main phase (45 s(-1)) accounting for 92% of the signal. SecB considerably slows down HasA folding. At stoichiometric amounts of SecB and HasA, a single phase (0.014 s(-1)) of refolding is observed. Two double point mutants of HasA were made, abolishing two hydrogen bonds between N-terminal and C-terminal side chain residues. In both cases, the mutants essentially maintained the same secondary and tertiary structure as wild-type HasA and were fully functional. Refolding of both mutants was much slower than that of wild-type HasA and they were secreted essentially independently of SecB. We conclude that SecB has mainly an antifolding function in the HasA ABC secretion pathway. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|