title: Trading in cooperativity for specificity to maintain uracil-free DNA.
abstract: Members of the dUTPase superfamily play an important role in the maintenance of the pyrimidine nucleotide balance and of genome integrity. dCTP deaminases and the bifunctional dCTP deaminase-dUTPases are cooperatively regulated by dTTP. However, the manifestation of allosteric behavior within the same trimeric protein architecture of dUTPases, the third member of the superfamily, has been a question of debate for decades. Therefore, we designed hybrid dUTPase trimers to access conformational states potentially mimicking the ones observed in the cooperative relatives. We studied how the interruption of different steps of the enzyme cycle affects the active site cross talk. We found that subunits work independently in dUTPase. The experimental results combined with a comparative structural analysis of dUTPase superfamily enzymes revealed that subtile structural differences within the allosteric loop and the central channel in these enzymes give rise to their dramatically different cooperative behavior. We demonstrate that the lack of allosteric regulation in dUTPase is related to the functional adaptation to more efficient dUTP hydrolysis which is advantageous in uracil-DNA prevention.
authors.affiliation: Institute of Enzymology, Research Centre for Natural sciences, Hungarian Academy of sciences, Budapest, Hungary.
authors.forename: Judit E
authors.initials: JE
authors.lastname: Szabó
authors.affiliation: Institute of Enzymology, Research Centre for Natural sciences, Hungarian Academy of sciences, Budapest, Hungary.
authors.forename: Enikő
authors.initials: E
authors.lastname: Takács
authors.affiliation: Institute of Enzymology, Research Centre for Natural sciences, Hungarian Academy of sciences, Budapest, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Merényi
authors.affiliation: Institute of Enzymology, Research Centre for Natural sciences, Hungarian Academy of sciences, Budapest, Hungary.|Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budapest, Hungary.
authors.forename: Beáta G
authors.initials: BG
authors.lastname: Vértessy
authors.affiliation: Institute of Enzymology, Research Centre for Natural sciences, Hungarian Academy of sciences, Budapest, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Tóth
mesh_terms: D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008274:Magnesium / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009709:Nucleotide Deaminases / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D011755:Pyrophosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013050:Spectrometry, Fluorescence; D013942:Thymine Nucleotides / Q000096:biosynthesis; D014498:Uracil / Q000378:metabolism*
chemical_list: D013942:Thymine Nucleotides; D014498:Uracil; D004247:DNA; D009709:Nucleotide Deaminases; C019988:dCTP deaminase; D011755:Pyrophosphatases; C020020:dUTP pyrophosphatase; D008274:Magnesium; C024157:thymidine 5'-triphosphate