Download MendeleyStructural Insights into the Catalytic Mechanism of Phosphate Ester Hydrolysis by dUTPase
Barabas, O., Pongracz, V., Kovari, J., Wilmanns, M., Vertessy, B.G.(2004) J Biol Chem 279: 42907-42915
- PubMed: 15208312
- DOI: https://doi.org/10.1074/jbc.M406135200
- Primary Citation of Related Structures:
1RN8, 1RNJ, 1SEH, 1SYL - PubMed Abstract:
dUTPase is essential to keep uracil out of DNA. Crystal structures of substrate (dUTP and alpha,beta-imino-dUTP) and product complexes of wild type and mutant dUTPases were determined to reveal how an enzyme responsible for DNA integrity functions. A kinetic analysis of wild type and mutant dUTPases was performed to obtain relevant mechanistic information in solution. Substrate hydrolysis is shown to be initiated via in-line nucleophile attack of a water molecule oriented by an activating conserved aspartate residue. Substrate binding in a catalytically competent conformation is achieved by (i) multiple interactions of the triphosphate moiety with catalysis-assisting Mg2+, (ii) a concerted motion of residues from three conserved enzyme motifs as compared with the apoenzyme, and (iii) an intricate hydrogen-bonding network that includes several water molecules in the active site. Results provide an understanding for the catalytic role of conserved residues in dUTPases.
Organizational Affiliation:
Institute of Enzymology, Biological Research Center, Hungarian Academy of Science, Budapest, Karolina út 29-31, H-1113, Hungary.
