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Identification of the SSB binding site of Uracil DNA Glycosylase
Author(s) -
George Nicholas Patrick,
Liban Tyler J
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb49
Subject(s) - uracil dna glycosylase , deinococcus radiodurans , dna glycosylase , deamination , cytosine , uracil , dna , biochemistry , chemistry , escherichia coli , binding site , dna repair , biology , enzyme , gene
Uracil DNA glycosylases (UDGs) catalyze the removal of uracil bases that arise in DNA by spontaneous cytosine deamination and dUTP misincorporation by DNA polymerases. UDGs are found in all kingdoms of life and in many cases have been shown to interact functionally with single‐strand DNA‐binding proteins (SSBs). The structural mechanisms that govern UDG/SSB interactions and the in vivo significance of the complex are currently unknown. We present the X‐ray crystal structures of Escherichia coli UDG in complex with the 9 C‐terminal residues of E. coli SSB and of Deinococcus radiodurans UDG in complex with the 12 C‐terminal residues of D. radiodurans SSB. The structures reveal a conserved platform on each UDG for binding SSB. Alanine variants of UDG residues involved in binding the SSB C‐terminal peptides lead to dramatic weakening of the cognate UDG/SSB complexes. These structures and solution studies provide firm evidence for the identification of the SSB interaction platform on UDG. Future genetic studies will examine the importance of UDG/SSB interactions in E. coli cells.