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


Abstract

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 PDB Entries

Structure ID Release Date Resolution Structure Title
1ZZF 2006-03-14 The DNA-bound solution structure of HPV-16 E2 DNA-binding domain
1R8P 2004-11-23 HPV-16 E2C solution structure
2NNU 2007-01-09 1.59 Crystal Structure of the Papillomavirus DNA Tethering Complex E2:Brd4
2Q79 2007-10-16 1.8 Crystal Structure of single chain E2C from HPV16 with a 12aa linker for monomerization.
1DTO 2000-02-23 1.9 CRYSTAL STRUCTURE OF THE COMPLETE TRANSACTIVATION DOMAIN OF E2 PROTEIN FROM THE HUMAN PAPILLOMAVIRUS TYPE 16
1BY9 1999-04-27 2.2 CRYSTAL STRUCTURE OF THE E2 DNA-BINDING DOMAIN FROM HUMAN PAPILLOMAVIRUS TYPE-16: IMPLICATIONS FOR ITS DNA BINDING-SITE SELECTION MECHANISM
3MI7 2011-04-06 2.2 An Enhanced Repressor of Human Papillomavirus E2 Protein

Relevant UniProtKB Entries

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