Article Figures & Data
Figures
- Fig. 1.
Organization of the cpsECK30locus, which is located between galF and gnd on the E. coli E69 chromosome (17). Components of the Wzy-dependent polymerization pathway (wzx andwzy) 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 andwzc, are near the start of the cluster. The functions oforfX, orfY, and orfZ are unknown. Primers used for PCR amplification of selected regions are indicated, and the sequences are given in Table 2.
- Fig. 2.
PCR analysis of the wza-to-wzcregion from different group 1 K serotypes of E. coli (A) andKlebsiella (B). For reference, K. pneumoniae K20 strain 889/50 is also shown in panel A and E. coli K30 strain E69 is shown in panel B. PCR products identical in size (1.8 kb) were obtained for all of the strains tested, indicating a conservation of gene order between clusters.
- Fig. 3.
(A) JUMPstart sequences from polysaccharide gene clusters directing the synthesis of amylovoran (ams) (27), colanic acid (cps) (45), O7 antigen (wb*) (31), and the E. coliand Klebsiella group 1 capsule clusters examined in this study. Variations from the E. coli K30 sequence are highlighted in boldface. The two ops elements found in theE. coli O7 JUMPstart sequence are underlined. (B) Stem-loop structures which have been identified incpsECK30 and cpsKPK2. They are located immediately downstream of wzc and may function as transcription terminators.
- Fig. 4.
Diagrammatic representation of the region upstream ofcps in the E. coli and K. pneumoniaestrains investigated. The regions for E. coli E69 (17) and K. pneumoniae Chedid (2) are based on published data. The location and type of IS element identified, if any, is indicated. The putative ς54promoters and conserved JUMPstart elements are located between the IS elements (or orf2) and orfX, the first gene of each cluster.
Tables
- Table 1.
Bacterial strains used in this study
Strain Serotype Source E. coli A295b O8:K42:H− F. Ørskov Bi161-42 O9:K29:H− F. Ørskov E56b O8:K27:H− F. Ørskov E69 O9a:K30:H12 F. Ørskov E75 O9:K34:H− F. Ørskov K14a O9ab:K28:H− F. Ørskov N24c O9a:K55:H− F. Ørskov Su3973-41 O9:K31:H− F. Ørskov 2146 O9:K26:H− B. Jann 2150 O9:K37:H− B. Jann 2151 O9:K39:H9 B. Jann 2178 O8:K42:H− B. Jann Klebsiella A5054 O1:K1 F. Ørskov B5055 O1:K2 F. Ørskov 708 O12:K80 F. Ørskov 889/50 O1:K20 F. Ørskov 1702 O4:K42 F. Ørskov 6613 O2:K27 F. Ørskov - Table 2.
Primers used for PCR amplification of chromosomal DNA
Primer Location Sequencea JD109 wza 5′-AGCGACTACGATTTGGATAAGC JD89 wzc 5′-ACGGGCAATAACAGGAAAATA JD90 wcaO 5′-TATGTGGGGCGATTGACTCC JD53 wzx 5′-TTTCCGAAACACGCTTAAAA JD95 orfX 5′-TGCGCTTCCACATACCAGTTA JD99 orfX 5′-GAAAGCAAGCCCAATGTCAC GALF1 galF 5′-GGGCGATCTCTCCGAATACTC
