Table shows that tau protein has an exonuclease domain that is either 5'-3' or 3'-5' long and acts as an exonuclease all the way through the sequence. This suggests that tau protein cuts the target DNA sequence in two different directions, 5'-3' and 3'-5'. These cuts make it easier for the double helix to unwind and for the transposase domain to insert into the transposed telomeric sequence fragment. The DNA damage checkpoint implicates DisA (IPR023763), a DNA integrity scanning protein. DNA damage activates this checkpoint prior to asymmetric division. During sporulation, DisA generates spherical foci that rapidly traverse chromosomes in search of lesions. When a lesion is present, disA pauses at the lesion site. This triggers a cellular response that ultimately results in a transient halt in the initiation of sporulation.