96
and 0.37 M (NH.)SO. (Figure 11). This enzyme is different from the
4 L 4
Euglena nuclear RNA polymerase II which elutes between 0.18 and 0.21
M (NH,)S0, and is sensitive to a-amanitin. The mitochondrial enzyme is
4 2 4
insensitive to a-amanitin and rifampicin and demonstrates a DNA depend
ence bases upon actinomycin D inhibition and the requirements for added
DNA and all of the ribonucleotide substrates. Poly d(AT) is the pre
ferred template and optimal activity is observed with low concentrations
I I | j
of Mn and Mg
Attempts to concentrate the mitochondrial enzyme by rechromatography
on a smaller DEAE-Sephadex column or to further purify the activity by
gylcerol gradient centrifugation resulted in the loss of significant
activity. This loss was probably due to the prolonged time at 4C
necessary for these additional purification steps.