The C-terminus of dUTPase: observation on flexibility using NMR.

The dynamics of the C-terminus of the dUTPases from Escherichia coli and equine infectious anaemia virus (EIAV) were studied by 1H–15N nuclear magnetic resonance spectroscopy. The two enzymes differ with regard to flexibility in the backbone of the 15 most C-terminal amino acid residues, some of which are conserved and essential for enzymic activity. In the bacterial enzyme, the residues closest to the C-terminus are highly flexible and display a correlation time in the nanosecond time range. No similar high flexibility could be detected for the C-terminal part of EIAV dUTPase, indicating a different time range of flexibility.