Figure 2.

Yeast mitochondrial protein extracts do not ligate nicked DNA:RNA substrates. DNA ligase reactions were carried out on mitochondrial protein extracts in a manner similar to Figure 1, however, the substrate was a DNA:RNA duplex. The lower band (dT₁₆) indicates unligated substrate, while the upper bands (dT₃₂, dT₄₈ and dT₆₄) indicate products. The positive control (+) is substrate plus T4 DNA ligase; the negative control (–) is substrate alone.