Comparison of the integration sites of GI1–GI3 in B. petrii (on the top) and of GI3::tet R in B. bronchiseptica PS2 (below). Above the respective DNA sequences a schematic presentation of the integration regions is shown. In B. petrii GI1–GI3 is integrated in a tRNAGly gene (tRNA11) leading to an 18 bp duplication of the 3'-end of the tRNA (red boxes). On the left side of the integration side an inverted repeat (IR) is indicated. Upstream of the IR a gene encoding a tRNACys is located. In B. bronchiseptica GI3::tetR is once more integrated in a gene encoding a tRNAGly (tRNA45) leading to a 18 bp duplication of its 3'-end. Much alike in B. petrii the direct repeat sequence is followed by an inverted repeat (IR). Below the schematic presentations of the integration regions the respective DNA sequences of the integration sites are shown. The start points of the tRNA genes are indicated by horizontal arrows indicating transcriptional polarity of the genes followed by a bar marked with a star which indicates the end of the tRNA gene. Vertical arrows indicate the integration sites of the GIs in the tRNA genes. Related inverted repeat sequences (IR) present in both species are boxed. In the case of B. bronchiseptica the sequence position indicated is taken from the genome sequence of strain RB50 .