No full text
Article (Scientific journals)
DNA-binding mechanism of the Escherichia coli Ada O(6)-alkylguanine-DNA alkyltransferase.
Verdemato, P. E.; Brannigan, J. A.; Damblon, Christian et al.
2000In Nucleic Acids Research, 28 (19), p. 3710-8
Peer Reviewed verified by ORBi
 

Files


Full Text
No document available.

Send to



Details



Keywords :
Amino Acid Motifs; Amino Acid Sequence; Binding Sites; Calorimetry; DNA/chemistry/genetics/metabolism; DNA Methylation; DNA Repair; DNA, Single-Stranded/chemistry/genetics/metabolism; DNA-Binding Proteins/chemistry/metabolism; Entropy; Escherichia coli/enzymology; Models, Molecular; Molecular Sequence Data; Mutation/genetics; Nuclear Magnetic Resonance, Biomolecular; Nucleic Acid Conformation; O(6)-Methylguanine-DNA Methyltransferase/chemistry/metabolism; Protein Binding; Protein Structure, Secondary; Titrimetry
Abstract :
[en] The C-terminal domain of the Escherichia coli Ada protein (Ada-C) aids in the maintenance of genomic integrity by efficiently repairing pre-mutagenic O:(6)-alkylguanine lesions in DNA. Structural and thermodynamic studies were carried out to obtain a model of the DNA-binding process. Nuclear magnetic resonance (NMR) studies map the DNA-binding site to helix 5, and a loop region (residues 151-160) which form the recognition helix and the 'wing' of a helix-turn-wing motif, respectively. The NMR data also suggest the absence of a large conformational change in the protein upon binding to DNA. Hence, an O:(6)-methylguanine (O:(6)meG) lesion would be inaccessible to active site nucleophile Cys146 if the modified base remained stacked within the DNA duplex. The experimentally determined DNA-binding face of Ada-C was used in combination with homology modelling, based on the catabolite activator protein, and the accepted base-flipping mechanism, to construct a model of how Ada-C binds to DNA in a productive manner. To complement the structural studies, thermodynamic data were obtained which demonstrate that binding to unmethylated DNA was entropically driven, whilst the demethylation reaction provoked an exothermic heat change. Methylation of Cys146 leads to a loss of structural integrity of the DNA-binding subdomain.
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Verdemato, P. E.
Brannigan, J. A.
Damblon, Christian ;  Université de Liège - ULiège > Département de chimie (sciences) > Chimie biologique structurale
Zuccotto, F.
Moody, P. C.
Lian, L. Y.
Language :
English
Title :
DNA-binding mechanism of the Escherichia coli Ada O(6)-alkylguanine-DNA alkyltransferase.
Publication date :
2000
Journal title :
Nucleic Acids Research
ISSN :
0305-1048
eISSN :
1362-4962
Publisher :
Oxford University Press, Oxford, United Kingdom
Volume :
28
Issue :
19
Pages :
3710-8
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 27 November 2010

Statistics


Number of views
60 (0 by ULiège)
Number of downloads
0 (0 by ULiège)

Scopus citations®
 
16
Scopus citations®
without self-citations
15
OpenCitations
 
14

Bibliography


Similar publications



Contact ORBi