6t66

Crystal structure of the Vibrio cholerae replicative helicase (DnaB) with GDP-AlF4

spinqualitylabelsall models 6t66, resolution 3.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6t66 is a 6 chain structure with sequence from Vibrio cholerae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.9Å Ligands: ALF, GDP, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q9KUY7_VIBCH Participates in initiation and elongation during chromosome replication; it exhibits DNA-dependent ATPase activity and contains distinct active sites for ATP binding, DNA binding, and interaction with DnaC protein, primase, and other prepriming proteins.[ARBA:ARBA00003574][RuleBase:RU362085] Publication Abstract from PubMed 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. Study of the DnaB:DciA interplay reveals insights into the primary mode of loading of the bacterial replicative helicase.,Marsin S, Adam Y, Cargemel C, Andreani J, Baconnais S, Legrand P, Li de la Sierra-Gallay I, Humbert A, Aumont-Nicaise M, Velours C, Ochsenbein F, Durand D, Le Cam E, Walbott H, Possoz C, Quevillon-Cheruel S, Ferat JL Nucleic Acids Res. 2021 Jun 21;49(11):6569-6586. doi: 10.1093/nar/gkab463. PMID:34107018 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Helicase 3D structures

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