We did not find significant array degradation downstream the insertion. We suspect that integrating into a spacer in the arrays and keeping a small size allow these elements to not disrupt CRISPR-Cas system function. 9/10

Aligning the DNA sequences that flank the ends of the tRNA- and array-targeting elements revealed a conserved DNA motif 40 to 50 bp away from the transposons left ends. 8/10

AlphaFold3-generated structures of TnsD proteins from A. franciscana (AfTnsD, array-targeting) and M. californica (McTnsD, tRNA-targeting) suggest that the C-terminal region absent in AfTnsD corresponds to a helix-turn-helix domain (HTH) used for DNA binding. 6/10

Unlike most Tn7-like elements, array-targeting transposons do not accumulate cargo genes, being consistently smaller and simpler. This contrasts with what is found even with the closely related tRNA-targeting elements. 5/10

A distinct structural difference that co-occurs with the change in att site used between these two elements is a C-terminal motif found in the tRNA-targeting TnsD proteins that is absent in the array-targeting group. 4/10

A similarity tree of nonredundant TnsD/TniQ proteins revealed that the array-targeting transposons are phylogenetically close to TnsD-mediated tRNA-targeting transposons in this phylum, a group that includes validated I-D and I-B2 CAST. 3/10

We found a novel family of Tn7-like transposable elements in Cyanobacteria which display a preference for insertion within CRISPR arrays, suggesting a previously unrecognized functional interplay between Tn7-like elements and CRISPR-Cas systems. 2/10