Effects of different combined mutations on levels of secreted FlgM. (A) Secreted levels of FlgM were determined for strains carrying different combined mutations, depicted by quantitative Western blot analysis using anti-FlgM antibody to detect FlgM in the supernatant of the spent growth medium (Sec FlgM, secreted FlgM; WC FlgM, whole cellular FlgM; WC DnaK, whole cellular DnaK). P*, parent strain, TH18500 (ΔaraBAD1156::flgM+). (B) Relative levels of secreted FlgM.