Km of PolyA polymerase in presence of Ap4A

Value 0.17 mM Range: ±0.025 mM
Organism Budding yeast Saccharomyces cerevisiae
Reference Sillero MA, De Diego A, Osorio H, Sillero A. Dinucleoside polyphosphates stimulate the primer independent synthesis of poly(A) catalyzed by yeast poly(A) polymerase. Eur J Biochem. 2002 Nov269(21):5323-9.PubMed ID12392566
Method Poly(A) polymerase from yeast was prepared. One unit of enzyme is the amount that incorporates 1 nmol of ATP (as AMP) into an acid insoluble form in 1 min at 37 °C. After incubation at 30 degrees or 37 degrees, the reaction mixtures were analyzed by TLC or HPLC
Comments Km calculated for S[0.5] (substrate at half of Vmax). The presence of Gp4G or Ap4A changed the kinetic from sigmoidal to hyperbolic,
Entered by Uri M
ID 103420