Poly(A) polymerase and poly(ADP‐ribose) polymerase activities in normal and crown gall tumor tissue cultures of tobacco

Abstract
Normal and crown gall tumor tissue cultures of tobacco had poly(ADP‐ribose) polymerase associated with the chromatin and two poly(A) polymerases (separable by DEAE‐Sephadex A‐25 chromatography) with the soluble fraction. The two poly(A) polymerases resembled mammalian enzymes in molecular mass (65–70 kDa), K m ATP (0.1–0.2 mM), primer and substrate preference (poly(A) and ATP, respectively), pH optimum (8–8.5), cation requirement (0.25 mM Mn2+/l mM Mg2+ = 5–15), inhibition by 3'‐dATP and spermine and lack of inhibition by α‐amanatin. Likewise the tobacco tumor tissue contained 4‐times higher activities of both poly(A) polymerases and 6‐times higher activity of poly(ADP‐ribose) polymerase as compared to the normal tissue indicating their enhanced function in transformed cells.