FIG. 1.
Organization of the cpsECK30 locus, which is located between galF and gnd on the E. coli E69 chromosome (17). Components of the Wzy-dependent polymerization pathway (wzx and wzy) are found in the region dedicated to K30 repeat unit synthesis and polymerization, along with the necessary glycosyltransferases, wbaP, wcaN, wcaO, and wbaZ. Genes involved in the translocation of capsular K30 antigen, wza and wzc, are near the start of the cluster. The functions of orfX, orfY, and orfZ are unknown. Primers used for PCR amplification of selected regions are indicated, and the sequences are given in Table 2.