FIG 4.

Southern blot analysis of TP_0144^com and TDE_0143^com. (a) The diagram shows how the erm cassette in the ΔTDE_0143 strain is replaced by P_tap1-aacC_m-P_tbpA-TP_0144 via allelic exchange recombination, generating the TP_0144^com strain. Predicted HindIII cut sites and the sizes of DNA fragments generated by HindIII near the locus of TDE_0143 are labeled. (b) Southern blot analysis. Purified chromosomal DNA and plasmids were treated with HindIII and then hybridized against two DNA probes: one is specific to TP_0144 (P₁₄₄), and the other is specific to aacC_m (P_Cm). Lane 1, ΔTDE_0143 chromosomal DNA (negative control); lane 2, pTP_0144C (positive control); lane 3, TP_0144^com chromosomal DNA. The numbers on the right represent the sizes of detected DNA fragments. (c) Physical map of pTDE_0143C. Predicted HindIII cut sites and the sizes of HindIII-digested DNA fragments are shown on the map. Additional details are depicted in Fig. 1b. (d) Southern blot analysis. The isolated plasmid DNAs were digested with HindIII and then hybridized against P_Cm and a TDE_0143-specific probe (P₁₄₃). Lanes 1, pTDE_0143C isolated from E. coli (positive control); lanes 2, the plasmids isolated from TDE_0143^com; lanes 3, pBFC (negative control). The numbers on the left represent the sizes of detected DNA fragments.