Figure 7

Assaying the formation of side products by T4 RNA ligases. Intermolecular strand-joining reactions containing 5'-adenylated adapters, 21-mer 5'-PO₄ RNA acceptors, and ligase (1 pmol) were incubated at 16°C overnight in the presence of 12.5% PEG 8000. Oligonucleotide substrates are depicted schematically above the gel. Grey lines represent RNA and black lines represent DNA. Products of the reaction were resolved on denaturing 15% acrylamide gels and stained with SYBR Gold. The bands corresponding to the input nucleic acids, the DNA adapter/RNA acceptor ligation product (39 bases), and larger side products are indicated. Ladder = size standard ladder, Rnl1 = T4 RNA ligase 1, Rnl2 = T4 RNA ligase 2, Rnl2tr = T4 RNA ligase 2 truncated, Rnl2 +MBP = T4 RNA ligase 2 truncated attached to an N-terminal maltose binding protein tag. All mutations indicated are substitutions in T4 Rnl2tr + MBP.