6hde
Structure of Escherichia coli dUTPase Q93H mutant
Structural highlights
Function[DUT_ECOLI] This enzyme is involved in nucleotide metabolism: it produces dUMP, the immediate precursor of thymidine nucleotides and it decreases the intracellular concentration of dUTP so that uracil cannot be incorporated into DNA.[HAMAP-Rule:MF_00116] Publication Abstract from PubMedProtein inhibitors of key DNA repair enzymes play an important role in deciphering physiological pathways responsible for genome integrity, and may also be exploited in biomedical research. The staphylococcal repressor StlSaPIbov1 protein was described to be an efficient inhibitor of dUTPase homologues showing a certain degree of species-specificity. In order to provide insight into the inhibition mechanism, in the present study we investigated the interaction of StlSaPIbov1 and Escherichia coli dUTPase. Although we observed a strong interaction of these proteins, unexpectedly the E. coli dUTPase was not inhibited. Seeking a structural explanation for this phenomenon, we identified a key amino acid position where specific mutations sensitized E. coli dUTPase to StlSaPIbov1 inhibition. We solved the three-dimensional (3D) crystal structure of such a mutant in complex with the substrate analogue dUPNPP and surprisingly found that the C-terminal arm of the enzyme, containing the P-loop-like motif was ordered in the structure. This segment was never localized before in any other E. coli dUTPase crystal structures. The 3D structure in agreement with solution phase experiments suggested that ordering of the flexible C-terminal segment upon substrate binding is a major factor in defining the sensitivity of E. coli dUTPase for StlSaPIbov1 inhibition. The Role of a Key Amino Acid Position in Species-Specific Proteinaceous dUTPase Inhibition.,Benedek A, Temesvary-Kis F, Khatanbaatar T, Leveles I, Suranyi EV, Szabo JE, Wunderlich L, Vertessy BG Biomolecules. 2019 Jun 6;9(6). pii: biom9060221. doi: 10.3390/biom9060221. PMID:31174420[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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