4AI4: crystal structure of E38Q mutant of 3-methyladenine DNA glycosylase I from Staphylococcus aureus

Citation:
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 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.
PDB ID: 4AI4Download
MMDB ID: 97340
PDB Deposition Date: 2012/2/8
Updated in MMDB: 2012/06
Experimental Method:
x-ray diffraction
Resolution: 1.73  Å
Source Organism:
Similar Structures:
Biological Unit for 4AI4: monomeric; determined by author and by software (PISA)
Molecular Components in 4AI4
Label Count Molecule
Protein (1 molecule)
1
DNA-3-methyladenine Glycosylase I
Molecule annotation
Chemicals (3 molecules)
1
1
2
2
* Click molecule labels to explore molecular sequence information.

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