Abstract
The enzyme dUTPase is essential in preventing uracil incorporation into DNA. Design of antagonist's against this novel chemotherapeutic target requires identification of species-specific differences in the structure and mechanism of the enzyme. This task is now approached via comparisons of available crystallographic structures of dUTPases from Homo sapiens, Escherichia coli, and retroviruses. The eukaryotic protein uniquely displays polar and charged amino acid residues participating in threefold intersubunit interactions. In bacterial and retroviral dUTPases, threefold interactions are mainly hydrophobic. The residues responsible for this contrast are mapped in multiple sequence alignment to positions differently and characteristically conserved in distinct evolutionary branches. The general feature of this contrast is further strengthened by a second eukaryotic model structure constructed using comparative modeling. The dUTPase cDNA from Drosophila melanogaster was identified, sequenced, and the model structure of the encoded polypeptide displayed a polar hydrogen-bonding network of threefold interactions, identically to the human structure. Results allow clear distinction between two subfamilies of trimeric dUTPases where altered subunit communication may account for a functional difference in the catalytic cycle.
Original language | English (US) |
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Pages (from-to) | 534-542 |
Number of pages | 9 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 279 |
Issue number | 2 |
DOIs | |
State | Published - Dec 20 2000 |
Externally published | Yes |
Keywords
- Allosterism
- Comparative modeling
- Drosophila melanogaster
- Hydropathy
- Intersubunit forces
- dUTPase
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology