Figure 2

Genetic map of csa operon, DNA and protein sequences of csaB . a) Genetic map of the csaB region on B. anthracis chromosome. The block arrows indicate the genes and the direction of transcription of the different genes. b) Nucleotide sequence of the wild type csaB gene and the location and nucleotide changes in the AP50^R mutants. Insertions and deletions are indicated by the red arrowheads and inverted arrowheads respectively. The various strains are indicated next to the mutated sites: derivatives of Sterne 34F₂ and JB220 are indicated by the prefixes S and J respectively. The mutant loci labeled in black were discovered by WGS and those in green by Sanger sequencing of csaB PCR fragments. The altered bases are indicated in blue with the changed base above the wild type. A693C and H270A mutations were genetically engineered mutants. The sequences at the beginning and end of the gene marked in pink are the junctions the csaB deletion mutant. c) Amino acid sequence of wild type and mutant CsaB proteins. The sites of truncation of CsaB protein due to frame-shift and nonsense mutations are indicated by blue downward arrows. The amino acid changes in non-synonymous mutants are indicated in blue above the wild type residue. The amino acid sequences of the frame-shift and truncated proteins are shown. The residues in red are the additional residues added due to the frame-shift before truncation of the mutant proteins. d) DNA and protein sequence of the csaB gene in csaB deletion mutant.