4ai4

Publication Abstract from PubMed

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 A 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.

A model for 3-methyladenine recognition by 3-methyladenine DNA glycosylase I (TAG) from Staphylococcus aureus.,Zhu X, Yan X, Carter LG, Liu H, Graham S, Coote PJ, Naismith J Acta Crystallogr Sect F Struct Biol Cryst Commun. 2012 Jun 1;68(Pt 6):610-5. Epub, 2012 May 22. PMID:22684054^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.