Similarity of RecJ motifs 1 and 2 with ExoI and ExoII motifs as exhibited by members of the RAD2-FEN-1 family of 5′ exonucleases. Sequences include E. coli RecJ, T4 RNase H, Taq polymerase, T7 gene 6 protein, S. cerevisiae RAD2, human XP-G, and murine FEN-1 with respect to the published alignment of the RAD2-FEN-1 group (24).