Fig. 1: ISDra2 MGE of the IS200/IS605 family.
From: Transposon-associated TnpB is a programmable RNA-guided DNA endonuclease
a, Schematic representation of the D. radiodurans ISDra2 locus. The MGE consists of the tnpA and tnpB genes flanked by left end (LE) and right end (RE) partially palindromic elements (shown in red and blue, respectively). Amino acid residues at the predicted RuvC nuclease active site are indicated above the tnpB gene. b, TnpA-mediated ‘peel and paste’ transposition mechanism for ISDra2. The TnpA dimer catalyses transposon excision from the lagging strand during DNA replication forming a circular single-stranded DNA intermediate and a donor joint. The excised transposon circle inserts at the acceptor joint into the lagging DNA strand 3′ to the TTGAT sequence, completing the transposition cycle. Transposon excision/insertion sites are marked by red triangles. c, Experimental workflow of the expression and purification of the TnpB complex from E. coli cells and bound RNA extraction. sRNA-seq, small RNA sequencing. d, Alignment of sRNA sequenced reads to the ISDra2 locus. The blue colour shows the RNA sequences derived from the RE element, and the green marks the last 16 nt at the sequenced RNA 3′ ends, which align with the transposon flanking DNA.
