Modularity and diversity of target selectors in Tn7 transposons

• DOI: 10.1016/j.molcel.2023.05.013
• Publication Date: 2023-06-01T14:55:58Z
• Authors: Guilhem Faure; Makoto Saito; Sean Benler; Iris Peng; Yuri I. Wolf; Jonathan Strecker; Han Altae-Tran; Edwin Neumann; David Li; Kira S. Makarova; Rhiannon K. Macrae; Eugene V. Koonin; Feng Zhang
• Keywords: Transposase; Modularity

To spread, transposons must integrate into target sites without disruption of essential genes while avoiding host defense systems. Tn7-like employ multiple mechanisms for target-site selection, including protein-guided targeting and, in CRISPR-associated (CASTs), RNA-guided targeting. Combining phylogenomic and structural analyses, we conducted a broad survey selectors, revealing diverse used by Tn7 to recognize sites, previously uncharacterized target-selector proteins found newly discovered transposable elements (TEs). We experimentally characterized CAST I-D system Tn6022-like transposon that uses TnsF, which contains an inactivated tyrosine recombinase domain, the comM gene. Additionally, identified non-Tn7 transposon, Tsy, encoding homolog TnsF with active show also inserts comM. Our findings modular architecture co-opt selectors from various sources optimize selection drive spread.