. 2002 Mar;184(6):1503–1513. doi: 10.1128/JB.184.6.1503-1513.2002

TABLE 2.

Influence of tonB1 mutations on TonB1 activity in P. aeruginosa and E. coli

Plasmid	TonB^a	Zone of growth (diam [cm])		Growth (OD₆₀₀) of E. coli KP1032^d
Plasmid	TonB^a	P. aeruginosa K1040^b	E. coli RK5015^c	Growth (OD₆₀₀) of E. coli KP1032^d
pQZ-06	Wild type	2.7	2.8	0.65
pMMB206		0	0
pQZ-A	Met1Leu	0	0	0.00
pQZ-C	ΔAsp260-Ala310	0	0	0.01
pQZ-CY	Cys36Gly	2.4	2.3	0.54
pQZ-H	His98Gly	2.6	0	0.02
pQZ-N1	ΔSer33-Ile67	0	0	0.04
pQZ-N2	ΔSer6-Pro83	0	0	0.03
pQZ-T	ΔPro82-Thr111	0	0	0.00
pQZ-Y1	Tyr264Ala	0	0	0.00
pQZ-Y2	Tyr264Phe	0	0	0.06
pQZ-P1	Pro265Ala	2.7	2.1	0.18
pQZ-P2	Pro265Gly	2.6	2.3	0.10
pQZ-Q1	Gln269Ala	2.5	2	0.77
pQZ-Q2	Gln293Ala	2.6	2.2	0.15
pQZ-V1	Val294Ala	2.7	2.3	0.12
pQZ-V2	Val294Thr	2.7	2.2	0.14
pQZ-E1	Glu274Ala	0	0	0.01
pQZ-E3	Glu274Ala/Asp304AsnN	2.5	0	0.02
pQZ-E2	Glu274Lys	0	0	0.03
pQZ-K1	Lys278Ala	1	0	0.04
pQZ-K2	Lys278Glu	1.1	0	0.00
pQZ-R1	Arg288Ala	2.2	2.5	0.94
pQZ-R2	Arg288Glu	2.3	2.5	0.79
pQZ-R3	Arg301Ala	2.5	2.6	0.45
pQZ-R4	Arg301Glu	2.6	2	0.60
pQZ-D1	Asp304Ala	0	0	0.02
pQZ-D2	Asp304Lys	0	0	0.03
pQZ-R5	Arg305Ala	2.5	2.6	0.67
pQZ-R6	Arg305Glu	2.7	2.5	0.38

Alterations present in the TonB1 proteins encoded by the indicated plasmids are highlighted.

The TonB1-deficient P. aeruginosa K1040 strain harboring wild-type tonB1 or the indicated tonB1 plasmids were plated onto the surface of an iron-deficient succinate minimal plate containing 180 μg of EDDHA/ml and 20 μM IPTG (to induce the tonB genes). Filter disks impregnated with 8 μl of pyoverdine (50-mg/ml stock) were placed on the plates, and the zones of growth (i.e., diameter) appearing after ca. 40 h at 37°C were measured. The data are representative of three separate experiments.

The tonB metE mutant E. coli strain RK5015 harboring wild-type tonB1 or the indicated tonB1 plasmids were plated onto the surface of glucose minimal plates containing 20 μM IPTG. Filter disks impregnated with 8 μl of vitamin B₁₂ (10 μM stock) were placed on the plates, and the zones of growth (i.e., diameter) appearing after ca. 40 h at 37°C were measured. The data are representative of three separate experiments.

The E. coli tonB mutant KP1032 carrying the indicated plasmids was inoculated into DTSB medium containing 50 μg of EDDHA/ml and 20 μM IPTG at an OD₆₀₀ of 0.05, and growth (i.e., the increase in cell density as measured by OD₆₀₀) was monitored for 10 h. The values for final OD₆₀₀ at 10 h are shown above. The data are representative of three independent experiments and have been corrected for background growth (OD₆₀₀ = 0.18) of KP1032 carrying pMMB206.