Study of the DnaB:DciA interplay reveals insights into the primary mode of loading of the bacterial replicative helicase
| Autor: | Jean-Luc Ferat, Adeline Humbert, Hélène Walbott, Claire Cargemel, Dominique Durand, Yazid Adam, Jessica Andreani, Eric Le Cam, Françoise Ochsenbein, Pierre Legrand, Sonia Baconnais, Inès Li de la Sierra-Gallay, Christophe Possoz, Sophie Quevillon-Cheruel, Magali Aumont-Nicaise, Christophe Velours, Stéphanie Marsin |
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| Přispěvatelé: | Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Gustave Roussy (IGR), Signalisation, noyaux et innovations en cancérologie (UMR8126), Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines - UFR Sciences de la santé Simone Veil (UVSQ Santé), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Models
Molecular AcademicSubjects/SCI00010 Protein Conformation dnaI 03 medical and health sciences chemistry.chemical_compound Bacterial Proteins Structural Biology dnaX Serine Genetics [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology Vibrio cholerae dnaB helicase 030304 developmental biology 0303 health sciences biology [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry Molecular Biology/Structural Biology [q-bio.BM] 030302 biochemistry & molecular biology Helicase DNA DnaA Cell biology DNA-Binding Proteins chemistry Replication Initiation biology.protein DnaB Helicases dnaC |
| Zdroj: | Nucleic Acids Research Nucleic Acids Research, Oxford University Press, 2021, 49 (11), pp.6569-6586. ⟨10.1093/nar/gkab463⟩ Nucleic Acids Research, 2021, 49 (11), pp.6569-6586. ⟨10.1093/nar/gkab463⟩ |
| ISSN: | 0305-1048 1362-4962 |
| Popis: | Replicative helicases are essential proteins that unwind DNA in front of replication forks. Their loading depends on accessory proteins and in bacteria, DnaC and DnaI are well characterized loaders. However, most bacteria do not express either of these two proteins. Instead, they are proposed to rely on DciA, an ancestral protein unrelated to DnaC/I. While the DciA structure from Vibrio cholerae shares no homology with DnaC, it reveals similarities with DnaA and DnaX, two proteins involved during replication initiation. As other bacterial replicative helicases, VcDnaB adopts a toroid-shaped homo-hexameric structure, but with a slightly open dynamic conformation in the free state. We show that VcDnaB can load itself on DNA in vitro and that VcDciA stimulates this function, resulting in an increased DNA unwinding. VcDciA interacts with VcDnaB with a 3/6 stoichiometry and we show that a determinant residue, which discriminates DciA- and DnaC/I-helicases, is critical in vivo. Our work is the first step toward the understanding of the ancestral mode of loading of bacterial replicative helicases on DNA. It sheds light on the strategy employed by phage helicase loaders to hijack bacterial replicative helicases and may explain the recurrent domestication of dnaC/I through evolution in bacteria. Graphical Abstract Graphical AbstractDciA is the antecedent but unrelated to the helicase loaders DnaC/I. Structurally, the N-terminal domain of DciA is related to the NTD of DnaA, whereas its CTD is unfolded. DciA associates with DnaB according to a 3/6 stoichiometry which loads the helicase more efficiently on DNA. We identified in DnaB proteins a determinant residue that discriminates DciA- and DnaC/I-helicases and which happens to be critical in vivo. The determinant residue is located at the center of the DciA binding site. |
| Databáze: | OpenAIRE |
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