title: The dimeric DNA binding domain of the human papillomavirus E2 protein folds through a monomeric intermediate which cannot be native-like.
abstract: The dimeric DNA binding domain of the human papillomavirus E2 protein displays a two-state concerted unfolding and dissociation, with no detectable monomeric intermediate species accumulated at equilibrium. We investigated the kinetic folding mechanism of the dimeric domain using stopped-flow spectroscopic techniques and observed a fast forming monomeric intermediate, followed by a slower bimolecular reaction. Both phases involve secondary structure rearrangements of similar magnitude. Our results support a folding pathway in which the formation of an early monomeric intermediate, with characteristics of hydrophobic collapse, is followed by a bimolecular step encompassing association and folding. The interwoven folding topology of this particular type of dimeric beta-barrel found in the E2 DNA binding domain strongly suggests that any monomeric species formed could not be native-like.
authors: MRC Unit for Protein Function and Design, Department of Chemistry, Cambridge University, UK.
authors: Y K
authors: YK
authors: Mok
authors: M
authors: M
authors: Bycroft
authors: G
authors: G
authors: de Prat-Gay
mesh_terms: D004268:DNA-Binding Proteins / Q000737:chemistry*; D017022:Flow Injection Analysis; D007700:Kinetics; D008958:Models, Molecular; D009856:Oncogene Proteins, Viral / Q000737:chemistry*; D027383:Papillomaviridae / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D013057:Spectrum Analysis; D013816:Thermodynamics
chemical_list: D004268:DNA-Binding Proteins; C054855:E2 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D011994:Recombinant Proteins