Fig. 1: IS110 mobile genetic elements express a ncRNA that is bound by its encoded recombinase.
From: Bridge RNAs direct programmable recombination of target and donor DNA
a, Schematic representation of the IS110 recombinase protein sequence. b, Schematic representation of the structure and life cycle of an IS110 element. Core sequences are depicted as green diamonds, the genomic target site is shown in blue and the non-coding ends are orange. Sequences are from IS621. c, A midpoint-rooted phylogenetic tree constructed from 1,054 IS110 recombinase sequences. d, Distribution of non-coding end lengths across eight IS families. The maximum of the LE and RE lengths is plotted for each family. Box plots show median (centre line), interquartile range (IQR) (box edges) and 1.5 × IQR (whiskers). Outliers not shown. n = 268 for IS110; n = 18–184 for other families (Extended Data Fig. 2). e, Small RNA-seq coverage plot of the concatenated non-coding ends of IS621 and five related orthologues expressed from their endogenous promoter in E. coli. Top, sequence logo of the conservation of the σ70 promoter motif. TSS, transcription start site. f, MST of a fluorescently labelled IS621 recombinase with either WT or scrambled ncRNA to measure the equilibrium dissociation constant (KD). Mean ± s.d. of three technical replicates. g, Consensus secondary structure of ncRNAs constructed from 103 IS110 LE sequences.
