A Model for 3-Methyladenine Recognition by 3-Methyladenine DNA Glycosylase I (Tag) from Staphylococcus Aureus.
Zhu, X., Yan, X., Carter, L.G., Liu, H., Graham, S., Coote, P.J., Naismith, J.H.(2012) Acta Crystallogr Sect F Struct Biol Cryst Commun 68: 610
- PubMed: 22684054
- DOI: https://doi.org/10.1107/S1744309112016363
- Primary Citation of Related Structures:
4AI4, 4AI5, 4AIA - PubMed Abstract:
The removal of chemically damaged DNA bases such as 3-methyladenine (3-MeA) is an essential process in all living organisms and is catalyzed by the enzyme 3-MeA DNA glycosylase I. A key question is how the enzyme selectively recognizes the alkylated 3-MeA over the much more abundant adenine. The crystal structures of native and Y16F-mutant 3-MeA DNA glycosylase I from Staphylococcus aureus in complex with 3-MeA are reported to 1.8 and 2.2 Å resolution, respectively. Isothermal titration calorimetry shows that protonation of 3-MeA decreases its binding affinity, confirming previous fluorescence studies that show that charge-charge recognition is not critical for the selection of 3-MeA over adenine. It is hypothesized that the hydrogen-bonding pattern of Glu38 and Tyr16 of 3-MeA DNA glycosylase I with a particular tautomer unique to 3-MeA contributes to recognition and selection.
Organizational Affiliation:
The BSRC, University of St Andrews, North Haugh, St Andrews KY16 9ST, Scotland.