FIG. 4.

(A) Genomic map of the tyrP region. Sequencing data revealed a 1,649-bp polymorphism containing a duplication of the tyrP and yccAΔ genes (14). Lines indicate the cutting sites of NruI resulting in 3,974- and 5,623-bp fragments, respectively. The bar indicates the region amplified by the duplication-PCR. (B) Southern blot analysis after Nru I digestion. The MUL-250 wild-type strain shows two bands of 3,974 and 5,623 bp, respectively, indicating the presence of both a single tyrP copy population and a double tyrP copy population. Clones obtained by the focus assay showed either a double copy (clone 38) or a single copy (clone 41). HeLa DNA was used as a negative control (line 4). (C) Agarose gel analysis of duplication-PCR products (93 bp). Screening of 60 C. pneumoniae strain MUL-250 clones revealed a single clone (clone 38) containing a duplicated tyrP gene as indicated by a positive PCR product. A negative duplication-PCR for clone 41 indicates the presence of a single tyrP copy only. The MUL-250 wild-type strain was used as a positive control, and H₂O was used as a negative control (lane 4).