FIG. 1.

(A) Schematic representation of the 2,655-bp fragment of class 1 integron in P. aeruginosa strain P11. Cassettes are represented by arrowheads, and their 59-base elements are represented by ellipses. (B) Sequence of the noncoding cassette (boldface type). Adenines and thymines of this cassette sequence repeated more than four times are underlined. The 59-be fragment in the linear form is shown in italic type. (C) 59-be structure of the noncoding cassette. The sequence shown is that present in circular form. Putative intI1 binding domains at the LH (1L and 2L) and RH (1R and 2R) sites described by Stokes et al. (13) are shown in boldface type, with their orientations indicated by the arrows above the sequences.