FIG. 2.

SDS-PAGE profile of fractions from complex purification. A sample from each step of purification was separated by SDS-PAGE and stained with silver nitrate. Results for protein size standards (M), cleared mitochondrial lysate (Cr), and pooled editing activity-positive fractions from SP Sepharose (SP), Q Sepharose (Q), and Superose 6 (S6) columns are presented. Glycerol gradient fractions 1 to 10 (fraction 1 is at the top) are shown (fractions 11 to 23 are not shown since essentially no protein was detected in these fractions). The numbers on left indicate the sizes of molecular mass markers, in kilodaltons. The most purified editing activity-positive fraction from the glycerol gradient (7) shows 20 major polypeptide bands.