Preparation of an antibody against a maize DNA polymerase holoenzyme: identification of the polymerase catalytic subunit

Three different DNA polymerase activities can be separated from germinating maize axes through DEAE – cellulose chromatography. Of these, DNA polymerase 2 appears to be a replicative-type enzyme composed of several subunits. An antibody has been developed against the DNA polymerase 2 multisubunit complex, which mainly recognizes a polypeptide of molecular weight around 90 kDa. Polypeptides of molecular mass of 83, 70, 60, 55, 45, and 24 kDa are also recognized. Activity gels showed that the 90-kDa polypeptide possesses catalytic activity. DNA polymerases 1 and 3 are not recognized by the antibody and their activities are not reduced. However, DNA polymerase 2 activity is reduced by 70%. The nature of the different DNA polymerase accompanying subunits is discussed. Key words: DNA polymerases, maize embryo axes.