The DNA recognition subunit of a DNA methyltransferase is predominantly a molten globule in the absence of DNA

FEBS Letters

Price, Nicholas C.¹  Waltho, Jonathan²  Hornby, David P.²  Shore, Paul²  Whitmarsh, Alan²  Baldwin, Geoffrey S.²  Kelly, Sharon M.¹  Pinarbasi, Hatice² 

[1] Department of Biological and Molecular Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK;Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK

关键词: DNA methylase;    Molten globule;    Binding specificity;    Nuclear magnetic resonance;    Circular dichroism;    C5 MTase;    cytosine (C5)-specific DNA methyltransferase;    NMR;    nuclear magnetic resonance;    CD;    circular dichroism;    AdoMet;    S-adenosyl methionine;    ANS 1-anilinonaphthalene-8-sulphonate;    TRD;    target recognition domain;   

DOI  :  10.1016/0014-5793(94)01171-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Enzyme-catalysed DNA methylation provides an opportunity for the modulation of protein-DNA recognition in biological systems. Recently we have demonstrated that the smaller of the two subunits of the heterodimeric, cytosine-specific DNA methyltransferase, M.AquI, is largely responsible for sequence-specific DNA recognition. Here we present evidence from a series of NMR, fluorescence and circular dichroism spectroscopy experiments that the DNA binding subunit of M.AquI has the characteristics of a molten globule in the absence of the catalytic machinery. In this metastable state this subunit retains its ability to bind DNA in a sequence-specific manner. We believe this finding offers an insight into the structural flexibility which underpins the mechansim of action of these enzymes, and may provide a possible biological role for molten globules in protein function.

【 授权许可】

Unknown