Fig. 8.

Schematic illustration of possible DNA inversion events leading to the UU172 element observed in strain V892. In a first inversion event, part ‘b’ of the ORF UU144 was fused, in frame, to UU172C and UU172N was fused to part ‘c’ of UU144. In a second inversion event at the inverted repeat ATTTAAATTAT, UU172N was joined, in frame, with the intergenic region in front of UU171, thereby creating a long ORF comprising UU172N, UU171, part of UU144 and UU172C.