FIG 3.

O-antigen acetylation and OafA expression from plasmid and chromosomally expressed protein. (A) LPS immunoblot with crude LPS extracts from Salmonella enterica serovar Typhimurium; LT2 basal O-antigen strain expressing OafA from pBADcLIC plasmid (pWT OafA-His), LT2 wild-type (WT) O-antigen strain with a C-terminal Deca-His tag added to the chromosomal copy of OafA (cWT OafA-His), the same strain with unmodified OafA (cWT OafA), and the LT2 basal O-antigen strain with an empty pBADcLIC plasmid (empty vector). O:5 antibody binding (blue) shows abequose acetylation, and Salmonella LPS core antibody binding (green) acts as a loading control. (B) Corresponding anti-His Western blot of insoluble protein fraction for detection of His-tagged OafA. The arrow indicates the full-length OafA protein.