Figure 7. Model for the origin of the D2 gene cluster by “recombination” between groups E and D1 gene clusters.

An H-repeat element present on a plasmid-based E-like gene cluster mediates a transposition event into the D1 gene cluster, with “resolution” of the intermediate cointegrate by homologous recombination in wbaN, instead of by a resolvase. Model based on replicative transposition. Modified from [32]..