Sensitivity of E. coli MB97 ΔfhuA and MB99 ΔfhuA tonB expressing plasmid-encoded FhuA derivativesa

StrainSensitivityb to:
T5φ80Colicin MAlbomycinMicrocin J25
MB97 ΔfhuA expressing:
    Wild-type FhuA (pHK570)5 (6)644 (5)2 (3)
    FhuAΔ5-160 (pBK570)d
    FhuAΔ5-160 (pBK570) + FhuA1-160 (pCEc761)5 (6)63 (4)3 (4)
    FhuAΔ5-160 (pBK570) + FhuA1-160 Δ5-17 (pCEc762)6
    FhuAΔ5-160 (pBK570) + FhuA1-160 CPc (pCEc773)
    FhuAΔ5-160 (pBK7) + FhuA1-160 (pCEcSU1)5 (6)6440 (1)
    FhuAΔ5-160 (pBK7) + FhuA1-357 (pMBlc7)5 (6)644 (5)
    FhuAΔ5-160 CP (pMBS77) + FhuA1-160 (pCEcSU1)
    FhuA E571R (pFE22)1 (2-4)0 (1-3)0 (1)
    FhuA E571R (pFE22) + FhuAΔ5-160 (pBK570)5 (6)62 (3)1 (2)
    FhuA E522R (pFE18)0 (1-3)(0-3)(0)
    FhuA E522R (pFE18) + FhuAΔ5-160 (pBK570)5 (6)62 (3)1 (2)
    FhuA V11D (p76SH15)5 (6)(0)
    FhuA V11D (p76SH15) + FhuA1-160 (pCEcSU1)5 (6)(0)
    FhuAΔ5-17 (pFhuA517)6
    FhuAΔ5-17 (pFhuA517) + FhuA1-160 (pCEcSU1)6
MB99 ΔfhuA tonB expressing:
    FhuAΔ5-160 (pBK570) + FhuA1-160 (pCEc761)6
    FhuAΔ5-160 (pBK570) + FhuA1-160 Δ5-17 (pCEc762)6
  • a Sensitivities to the ligands were tested by using E. coli MB97 ΔfhuA or MB99 ΔfhuA tonB freshly transformed with the indicated plasmids. The sensitivities to phages T1, T5, and φ80 and to colicin M, microcin J25, and albomycin were tested by spotting 3 μl of 10-fold or 3-fold (albomycin and microcin J25) dilutions onto TY agar plates overlaid with TY top agar containing the strain to be tested.

  • b The results are given as the last of a 10-fold or 3-fold dilution series that resulted in a clear zone of growth inhibition. Numbers in parentheses indicate turbid inhibition zones.

  • c CP, cytoplasmic (the protein was expressed without its signal sequence).

  • d —, no growth inhibition and no phage plaques.