While specific sites of CPS cleavage for DpoAPK37.1 were not determined in this study, it is clear that the absence of the d-GlсpNAc side branch is necessary for susceptibility to infection by phage APK37.1, and the purified depolymerase digests K3-v1 CPS but not K3 (O. Timoshina and M. Shneider, unpublished observations). Here, CAD is linked to infection.