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The EMBO Journal (1998) 17, 3640–3650, doi:10.1093/emboj/17.13.3640

Table 2
Overlapping functions of components of a bacterial Sec-independent protein export pathway
Frank Sargent, Erik G. Bogsch, Nicola R. Stanley, Margaret Wexler, Colin Robinson, Ben C. Berks and Tracy Palmer
Table 2: A comparison of enzyme activities in tat mutants
Enzyme Fraction Activity (U/g of cells)
MC4100 parent strain ELV15 DeltatatA J1M1 DeltatatE JARV15 DeltatatADeltatatE
TMAO reductasea periplasm 115 28 20 1.1
membrane 4.4 1.0 1.5 <0.01
cytoplasm 14 44 39 45
DMSO reductaseb periplasm 0.05 0.02 0.07 <0.01
membrane 1.5 0.18 0.90 0.14
cytoplasm <0.01 1.9 0.54 3.1
Nitrate reductasec periplasm 3.0 3.5 4.1 2.0
membrane 36 59 56 55
cytoplasm 1.2 2.9 2.0 2.8
Fumarate reductased periplasm <0.01 <0.01 <0.01 <0.01
membrane 2.3 7.6 5.8 7.3
cytoplasm 0.18 1.2 2.0 1.4
beta-Lactamasee (pBR322) total exportedf 0.99 0.99 nd 0.93
cytoplasm 0.04 0.02 nd <0.01
Acid phosphatasea periplasm 5.8 5.9 5.0 4.3

Oxidoreductase activities are expressed as substrate-dependent benzyl viologen oxidations (units are mumol of benzyl viologen oxidized per min). beta-Lactamase activities were determined as mumol of 7-(thienyl-2-acetamido)-3-[2-(4-N,N-dimethylaminophenylazo)pyridinium-methyl]-3-cephem-4 carboxylic acid (PADAC) hydrolysed per min. Acid phosphatase activities were determined as mumol of p-nitrophenyl phosphate hydrolysed per min.

Cells were grown anaerobically with 0.5% glycerol and 0.4%

aTMAO,

bDMSO,

cnitrate,

dfumarate or

e0.2% glucose with 0.4% nitrate.

f'Total exported' combines activities from both periplasm and culture media.

nd = not determined.
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