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Title: Kinetics of uptake and incorporation of meso-diaminopimelic acid in different Escherichia coli strains

Abstract

The rate at which the peptidoglycan precursor meso-diaminopimelic acid (DAP) is incorporated into the cell wall of Escherichia coli cells was determined by pulse-label experiments. For different E. coli strains, the incorporation rate was compared with the rate of uptake of DAP into the cell. With E. coli W7, a dap lys mutant generally used in this kind of studies, steady-state incorporation was reached only after about 0.75 of the doubling time. This lag period can be ascribed to the presence of a large internal DAP pool in the cells. An E. coli K-12 lysA strain was constructed which could be grown without DAP in its medium. Consequently, due to the higher specific activity of the added (TH)DAP, faster incorporation and higher levels of radioactivity in the peptidoglycan layer were observed in the K-12 lysA strain than in the W7 strain. In addition, uptake and incorporation were faster in steady state (within about 0.2 of the doubling time), indicating a smaller DAP pool. The lag period could be further diminished and the incorporation rate could be increased by feedback inhibition of the biosynthetic pathway to DAP with threonine and methionine. These results make MC4100 lysA a suitable strain for studiesmore » on peptidoglycan synthesis. To explain our observations, the authors suggest the existence of an expandable pool of DAP in E. coli which varies with the DAP concentration in the growth medium.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Univ. of Amsterdam, Netherland
OSTI Identifier:
6298091
Resource Type:
Journal Article
Journal Name:
J. Bacteriol.; (United States)
Additional Journal Information:
Journal Volume: 1
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; GLUCOPROTEINS; KINETICS; UPTAKE; TRITIUM COMPOUNDS; CELL WALL; ESCHERICHIA COLI; FEEDBACK; BACTERIA; CARBOHYDRATES; CELL CONSTITUENTS; LABELLED COMPOUNDS; MICROORGANISMS; ORGANIC COMPOUNDS; PROTEINS; SACCHARIDES; 550201* - Biochemistry- Tracer Techniques

Citation Formats

Wientjes, F B, Pas, E, Taschner, P E, and Woldringh, C L. Kinetics of uptake and incorporation of meso-diaminopimelic acid in different Escherichia coli strains. United States: N. p., 1985. Web.
Wientjes, F B, Pas, E, Taschner, P E, & Woldringh, C L. Kinetics of uptake and incorporation of meso-diaminopimelic acid in different Escherichia coli strains. United States.
Wientjes, F B, Pas, E, Taschner, P E, and Woldringh, C L. Tue . "Kinetics of uptake and incorporation of meso-diaminopimelic acid in different Escherichia coli strains". United States.
@article{osti_6298091,
title = {Kinetics of uptake and incorporation of meso-diaminopimelic acid in different Escherichia coli strains},
author = {Wientjes, F B and Pas, E and Taschner, P E and Woldringh, C L},
abstractNote = {The rate at which the peptidoglycan precursor meso-diaminopimelic acid (DAP) is incorporated into the cell wall of Escherichia coli cells was determined by pulse-label experiments. For different E. coli strains, the incorporation rate was compared with the rate of uptake of DAP into the cell. With E. coli W7, a dap lys mutant generally used in this kind of studies, steady-state incorporation was reached only after about 0.75 of the doubling time. This lag period can be ascribed to the presence of a large internal DAP pool in the cells. An E. coli K-12 lysA strain was constructed which could be grown without DAP in its medium. Consequently, due to the higher specific activity of the added (TH)DAP, faster incorporation and higher levels of radioactivity in the peptidoglycan layer were observed in the K-12 lysA strain than in the W7 strain. In addition, uptake and incorporation were faster in steady state (within about 0.2 of the doubling time), indicating a smaller DAP pool. The lag period could be further diminished and the incorporation rate could be increased by feedback inhibition of the biosynthetic pathway to DAP with threonine and methionine. These results make MC4100 lysA a suitable strain for studies on peptidoglycan synthesis. To explain our observations, the authors suggest the existence of an expandable pool of DAP in E. coli which varies with the DAP concentration in the growth medium.},
doi = {},
journal = {J. Bacteriol.; (United States)},
number = ,
volume = 1,
place = {United States},
year = {1985},
month = {10}
}