TnsA is part of the Tn7 transposon mobile genetic element working together with TnsB, TnsC, and TnsD to facilitate insertion of the transposon. TnsA catalyzes cleavage at the transposon 5' ends, and TnsC is the activator of the composite TnsAB transposase. TnsA belongs to a superfamily of nucleases including very short patch repair (Vsr) endonucleases, archaeal Holliday junction resolvases, MutH methyl-directed DNA mismatch-repair endonucleases, and catalytic domains of many restriction endonucleases, such as EcoRI, BamHI, and FokI.
Jiyao W et al.(2023). "The conserved domain database in 2023.",