Solution Structure of the DNA-Binding Domain of a Human Papillomavirus E2 Protein: Evidence for Flexible DNA-Binding Regions

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• 作者：Heng Liang ; Andrew M. Petros ; Robert P. Meadows ; Ho Sup Yoon ; David A. Egan ; Karl Walter ; Thomas F. Holzman ; Terry Robins ; and Stephen W. Fesik
• 刊名：Biochemistry
• 出版年：1996
• 出版时间：February 20, 1996
• 年：1996
• 卷：35
• 期：7
• 页码：2095 - 2103
• 全文大小：547K
• 年卷期：v.35,no.7(February 20, 1996)
• ISSN：1520-4995

文摘

The three-dimensional structure of the DNA-binding domain of theE2 protein from humanpapillomavirus-31 was determined by using multidimensionalheteronuclear nuclear magnetic resonance(NMR) spectroscopy. A total of 1429 NMR-derived distance anddihedral angle restraints were obtainedfor each of the 83-residue subunits of this symmetric dimer. Theaverage root mean square deviations of20 structures calculated using a distance geometry-simulated annealingprotocol are 0.59 and 0.90 Å forthe backbone and all heavy atoms, respectively, for residues 2-83.The structure of the human virusprotein free in solution consists of an eight-stranded mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-barrel andtwo pairs of mages/gifchars/alpha.gif" BORDER=0>-helices. Although theoverall fold of the protein is similar to the crystal structure of thebovine papillomavirus-1 E2 proteinwhen complexed to DNA, several small but interesting differences wereobserved between these twostructures at the subunit interface. In addition, a mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-hairpinthat contacts DNA in the crystal structure ofthe protein-DNA complex is disordered in the NMR structures, andsteady-state ¹H-¹⁵NheteronuclearNOE measurements indicate that this region is highly mobile in theabsence of DNA. The recognitionhelix also appears to be flexible, as evidenced by fast amide exchangerates. This phenomenon has alsobeen observed for a number of other DNA-binding proteins and mayconstitute a common theme in protein/DNA recognition.