Fig. 1.

Structure of Polintons. Polintons from different species (DR, zebrafish; CI, sea squirt; XT, frog; CB, nematode; TC, beetle; SP, sea urchin; TV, T. vaginalis protist; GI, G. intraradices fungus) are schematically depicted as rectangles flanked by terminal inverted repeats (gray triangles). Target site sizes are indicated in square brackets. ORFs coding for Polinton-specific proteins are shown as color rectangles: black, INT; red, family B DNA polymerase (POLB); blue, the ATPase (marked by ATP and ATP1); orange, the cysteine PRO. Lavender (PZ), brown (PW), green (PX), yellow (PY), purple (PC1), navy blue (PC2), PTV1-PTV6, PGI 1, and PGI2 rectangles indicate unclassified proteins. Horizontal arrows show orientation of corresponding ORFs. Orientation of different Polintons was defined by direct orientation of their integrases.