THE IN-VITRO DNA-BINDING PROPERTIES OF NDP KINASE ARE RELATED TO ITS OLIGOMERIC STATE

Genetic and biochemical evidences suggest that the enzymatic activity of NDP kinase is necessary but not sufficient for its biological funct ion, While the human NDPK-B binds specifically single-strand polypyrim idines sequences, the hexameric enzyme from Dictyostelium does not, We demonstrated by electrophoretic mobility shift assay and filter bindi ng assay that a dimeric mutant from Dictyostelium binds to an oligodes oxynucleotide while the wild-type does not, These data suggest that th e differences in the DNA binding properties of several eucaryotic NDP kinases might be correlated to the differences in the stability of the ir hexameric structure. (C) 1997 Federation of European Biochemical So cieties.