(5)Tau protein's active function Table illustrates that the Tau protein contains domains that are associated with Telomerase ribonucleoprotein complex -RNA-binding 、 Telomere length regulation protein conserved 、 Telomere repeat-binding factor dimerisation 、 Telomere-associated protein Rif1 N-terminal 、 Telomeric single stranded DNA binding POT1 、 Shelterin complex subunit TPP1、 Protection of telomeres protein 1 ssDNA-binding、 Restriction of telomere capping protein 4 C-terminal、CST complex subunit Stn1 N-terminal. The Tau protein's telomere binding region, primarily located at the C-terminal, regulates the length of telomeres. The tau protein binds to the CCCTAA/TTAGGG repeat sequence, but it doesn't have the functional domain that is needed to make telomere fragments. Table demonstrates the telomere reverse transcriptase activity of tau protein. The cut region is "TAA," and tau protein will cut double-stranded fragments from telomeres in the same manner as reverse transcriptase, as indicated by retrotransposon gag and reverse transcriptase. Table illustrates that the tau protein contains a telomere repair-related domain ku, which repair truncated telomere sequences by facilitating the homologous recombination repair of DNA double-strand breaks and the recovery of stalled replication forks. (1) Domains of transposases Transposable element P transposase (IPR048366) represents the GTP-binding insertion domain (GBD) of the transposable element P transposase from the fruit fly Drosophila melanogaster (TNP) and its human homolog, the DNA transposase THAP9. This domain is inserted into the RNaseH domain and primarily acquires an α-helical fold that is similar to that of Hermes, Tn5, or RAG1 proteins. This domain facilitates protein-DNA interactions. TNP is specifically involved in the transposition of P elements, as well as precise and imprecise excision. It possesses unique functions, including the generation of long staggered DNA breaks during transposition and the need for a guanosine triphosphate cofactor. THAP9 specifically recognizes the bipartite 5'-TXXGGGX(A/T)-3' consensus motif, facilitating transposition.