Equilibrium dissociation and unfolding of the dimeric human papillomavirus strain-16 E2 DNA-binding domain.


The equilibrium unfolding reaction of the C-terminal 80-amino-acid dimeric DNA-binding domain of human papillomavirus (HPV) strain 16 E2 protein has been investigated using fluorescence, far-UV CD, and equilibrium sedimentation. The stability of the HPV-16 E2 DNA-binding domain is concentration-dependent, and the unfolding reaction is well described as a two-state transition from folded dimer to unfolded monomer. The conformational stability of the protein, delta GH2O, was found to be 9.8 kcal/mol at pH 5.6, with the corresponding equilibrium unfolding/dissociation constant, Ku, being 6.5 x 10(-8) M. Equilibrium sedimentation experiments give a Kd of 3.0 x 10(-8) M, showing an excellent agreement between the two different techniques. Denaturation by temperature followed by the change in ellipticity also shows a concomitant disappearance of secondary and tertiary structures. The Ku changes dramatically at physiologically relevant pH's: with a change in pH from 6.1 to 7.0, it goes from 5.5 x 10(-8) M to 4.4 x 10(10) M. Our results suggest that, at the very low concentration of protein where DNA binding is normally measured (e.g., 10(-11) M), the protein is predominantly monomeric and unfolded. They also stress the importance of the coupling between folding and DNA binding. Study holds ProTherm entries: 9322, 9323, 9325, 9326, 9327, 9328 Extra Details: dimer; E2 DNA-binding domain; equilibrium unfolding;,human papillomavirus

Submission Details

ID: qFytjcBn

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:37 p.m.

Version: 1

Publication Details
Mok YK;de Prat Gay G;Butler PJ;Bycroft M,Protein Sci. (1996) Equilibrium dissociation and unfolding of the dimeric human papillomavirus strain-16 E2 DNA-binding domain. PMID:8745409
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Regulatory protein E2 P03120 VE2_HPV16
99.4 Regulatory protein E2 P0DKA0 VE8E2_HPV16