Selective modification of one (of three) tyrosine residue per enzyme monomer lends to inactivation of dUTPase of the retrovirus equine infectious anemia virus (EIAV). The substrate dUMP and the cofactor Mg2+ protects against inactivation and modification, in agreement with the study on E. coli dUTPase. Amino acid analyses of nitrated dUTPases confirmed Tyr-selectivity of modification. The nitrated residue in E. coli dUTPase was identified as the evolutionary highly conserved Tyr-93. The modifiable residue is shown to be the only Tyr exposed in both E. coli and EIAV dUTPases. As a consequence of Tyr-93 derivatization, the Mg2+-dependent interaction between the substrate-analogue dUDP and E. coli dUTPase becomes impaired as shown by circular dichroism spectroscopy, here presented as a tool for monitoring ligand binding to the active site.
|Number of pages||7|
|Journal||Biochemical and biophysical research communications|
|Publication status||Published - Feb 15 1996|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology