#*** ''' The chromosome shares a common ‘backbone’ sequence ∼3.9 Mb with those of E.coli K12 (MG1655) (10) and O157 (EDL933) (11), which is essentially collinear. However, the backbone sequence is interrupted by numerous segments of K12‐, O157‐ and Shigella‐specific DNA, designated ‘K‐islands’ (KIs), ‘O‐islands’ (OIs) and ‘S‐islands’ (SIs), respectively (Fig. 1, circle 1). The co‐linearity is also broken by numerous inversions and translocations compared with the E.coli sequences ''' | #*** ''' The chromosome shares a common ‘backbone’ sequence ∼3.9 Mb with those of E.coli K12 (MG1655) (10) and O157 (EDL933) (11), which is essentially collinear. However, the backbone sequence is interrupted by numerous segments of K12‐, O157‐ and Shigella‐specific DNA, designated ‘K‐islands’ (KIs), ‘O‐islands’ (OIs) and ‘S‐islands’ (SIs), respectively (Fig. 1, circle 1). The co‐linearity is also broken by numerous inversions and translocations compared with the E.coli sequences ''' |