Nucleic Acids Research, 1978, Vol. 5, No. 8 3043-3056
© 1978
Articles |
Purification and properties of DNA-dependent DNA-polymerases from Neurospora crassa
Max-Planck-Institut für Biochemie 8033 Martinsried, GFR
Received April 5, 1978.
Two DNA-dependent DNA-polymerases (E.C. 2.7.7.7 [EC] ) are partially purified from the high speed supernatant of mechanically disrupted hyphae of Neurospora crassa WT 74A. Some properties such as temperature and pH optimum and the optimal concentra tions for Mg2+ Zn2+ NH4+ and Na+ are very similar.
On the other hand these enzymes show different properties on ion-exchange columns, are weil distinguished by molecular weight (147 000 d and 110 000 d for A and B resp.) and the stimulatio by K+ differs (K+ optimum for A: 570 mM and for B: 45 mM). Mn2+ and Zn2+ inhibit incorporation of deoxyribonucleoside monophos phates between 70 and 90%.
Our best preparations so far have specific activities of 13 200 units/mg protein for A and 12 000 units/mg protein for B.
*with the technical assistance of Helga Riesemann