FIG. 3.

The type I deletions can be grouped into the following 12 categories: B52 (D22), H122 (H148), F10, G113 (G92 and G95), Y54 (Y34, Y42, Y50, and Y59), E26 (HB101, W2914, and W2915), Z22 (Z27, Z28, and Z57), Z14 (Z29), Y39 (Y4, Y5, Y15, Y24, Y26, Y35, Y45, Y46, Y49, Y58, and Y60), Y52 (Y51 and Y53), Z20 (Z24), and E41. The deletions are displayed as thick lines. Comparisons of the deletion lengths distinguish variable and common deleted regions. At the opposite end from the IS element, the last open reading frame in the common deleted region is crl. The IS30 element is inserted inside an inactivated single copy of IS911. The distances are given (in kilobases) according to the published E. coli K-12 genome (6).