Figure 1. General structure of GInts.

The GInt element (orange, with bacterial sequences in grey) has a tripartite structure: The highly conserved ginABCD operon, the cargo DNA (broken line), and a 0.2–0.4 kb poorly conserved 3′ end. GInts integrate site-specifically; the GInt carrying the Pht-PAI from P. syringae pv. phaseolicola 1448A, and related elements, integrate within a putative ABC transporter gene (PSPPH_4293 in strain 1448A; indicated as ABC). Small grey and orange arrows represent primers for testing excision and circularization. The site-specific integration of GInts generates two direct imperfect repeats (attL and attR) of 10 and 11 nucleotides, which are chimeras of the attI sequence from the GInt (orange letters) and the attB sequence from the bacterial chromosome (grey lettering). The sequence logo was generated from alignments of the att repeats from GInts related to the Pht-PAI (Table S1).