Fig 1.

Mutations in the patA1 and patA2 genes cause chain length phenotypes in Bacillus anthracis vegetative forms. (A) Genes for the PatA1 and PatA2 acetyltransferases are located on the Bacillus anthracis chromosome immediately adjacent to genes for the major S-layer proteins (sap and eag) and to csaB, which encodes a ketal pyruvyl transferase essential for S-layer formation. (B) DIC microscopy images of vegetative forms germinated from B. anthracis wild-type and csaB, bslO, patA1, patA2, and patA1 patA2 mutant spores. Scale bar, 10 μm. (C) The chain lengths of 100 vegetative bacilli were quantified for each strain; the data are presented as a box-and-whiskers plot, where the size of each box is defined by the boundaries of the 25th and 75th percentiles, the whiskers are the maximum and minimum measured lengths, and the center bar indicates the median length. Data were examined with an unpaired two-tailed Student's t test. A significant difference (P < 0.0001) relative to wild-type is indicated with an asterisk (*). The patA1 patA2 mutant was also compared to mutants with singular deletions of patA1 and patA2 genes. (D) The B. anthracis patA1 patA2 mutant strain was transformed with pAD123, i.e., the empty vector, pML360, a plasmid expressing patA1-patB1, or pML301, a plasmid expressing patA2-patB2. A significant difference (P < 0.0001) between the empty vector and the pML360 and pML301 strains was observed after data sets were compared with a Student t test.