scholarly journals Polyamines Are Not Required for Aerobic Growth of Escherichia coli: Preparation of a Strain with Deletions in All of the Genes for Polyamine Biosynthesis

2009 ◽  
Vol 191 (17) ◽  
pp. 5549-5552 ◽  
Author(s):  
Manas K. Chattopadhyay ◽  
Celia White Tabor ◽  
Herbert Tabor
Keyword(s):  
Escherichia Coli ◽  
Ornithine Decarboxylase ◽  
Arginine Decarboxylase ◽  
Strictly Anaerobic ◽  
Lysine Decarboxylase ◽  
Free Medium ◽  
Aerobic Growth ◽  
Anaerobic Conditions ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase

ABSTRACT A strain of Escherichia coli was constructed in which all of the genes involved in polyamine biosynthesis—speA (arginine decarboxylase), speB (agmatine ureohydrolase), speC (ornithine decarboxylase), spe D (adenosylmethionine decarboxylase), speE (spermidine synthase), speF (inducible ornithine decarboxylase), cadA (lysine decarboxylase), and ldcC (lysine decarboxylase)—had been deleted. Despite the complete absence of all of the polyamines, the strain grew indefinitely in air in amine-free medium, albeit at a slightly (ca. 40 to 50%) reduced growth rate. Even though this strain grew well in the absence of the amines in air, it was still sensitive to oxygen stress in the absence of added spermidine. In contrast to the ability to grow in air in the absence of polyamines, this strain, surprisingly, showed a requirement for polyamines for growth under strictly anaerobic conditions.

scholarly journals Overexpression of arginine decarboxylase in transgenic plants

1997 ◽  
Vol 325 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Daniel BURTIN ◽  
Anthony J. MICHAEL
Keyword(s):  
Transgenic Plants ◽  
Arginine Decarboxylase ◽  
Polyamine Metabolism ◽  
Morphological Development ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Two Generations ◽  
Key Enzyme ◽  
Polyamine Conjugate ◽  
And Control

The activity of arginine decarboxylase (ADC), a key enzyme in plant polyamine biosynthesis, was manipulated in two generations of transgenic tobacco plants. Second-generation transgenic plants overexpressing an oat ADC cDNA contained high levels of oat ADC transcript relative to tobacco ADC, possessed elevated ADC enzyme activity and accumulated 10–20-fold more agmatine, the direct product of ADC. In the presence of high levels of the precursor agmatine, no increase in the levels of the polyamines putrescine, spermidine and spermine was detected in the transgenic plants. Similarly, the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase were unchanged. No diversion of polyamine metabolism into the hydroxycinnamic acid–polyamine conjugate pool or into the tobacco alkaloid nicotine was detected. Activity of the catabolic enzyme diamine oxidase was the same in transgenic and control plants. The elevated ADC activity and agmatine production were subjected to a metabolic/physical block preventing increased, i.e. deregulated, polyamine accumulation. Overaccumulation of agmatine in the transgenic plants did not affect morphological development.

Complementation of a polyamine-deficient Escherichia coli mutant by expression of mouse ornithine decarboxylase

1987 ◽  
Vol 7 (1) ◽  
pp. 564-567
Author(s):  
M Macrae ◽  
P Coffino
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Enzymatic Activity ◽  
Ornithine Decarboxylase ◽  
Polyamine Biosynthesis ◽  
Coli Mutant ◽  
Terminal Amino ◽  
High Level ◽  
Carboxy Terminal ◽  
Exogenous Source

Mouse ornithine decarboxylase (ODCase) cDNA was expressed at a high level in an Escherichia coli mutant deficient in polyamine biosynthesis. The expression of mouse ornithine decarboxylase relieved the dependence of the mutant on an exogenous source of polyamines, presumably by providing putrescine, the product of the enzyme. The effect on the enzymatic activity of deletions that removed carboxy-terminal amino acids of the protein was determined.

scholarly journals Role of pyridoxal phosphate in mammalian polyamine biosynthesis. Lack of requirement for mammalian S-adenosylmethionine decarboxylase activity

1977 ◽  
Vol 166 (1) ◽  
pp. 81-88 ◽  
Author(s):  
A E Pegg
Keyword(s):  
Ornithine Decarboxylase ◽  
Pyridoxal Phosphate ◽  
Vitamin B ◽  
Decarboxylase Activity ◽  
Deficient Diet ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Ornithine Decarboxylase Activity

1. Polyamine concentrations were decreased in rats fed on a diet deficient in vitamin B-6. 2. Ornithine decarboxylase activity was decreased by vitamin B-6 deficiency when assayed in tissue extracts without addition of pyridoxal phosphate, but was greater than in control extracts when pyridoxal phosphate was present in saturating amounts. 3. In contrast, the activity of S-adenosylmethionine decarboxylase was not enhanced by pyridoxal phosphate addition even when dialysed extracts were prepared from tissues of young rats suckled by mothers fed on the vitamin B-6-deficient diet. 4. S-Adenosylmethionine decarboxylase activities were increased by administration of methylglyoxal bis(guanylhydrazone) (1,1′-[(methylethanediylidine)dinitrilo]diguanidine) to similar extents in both control and vitamin B-6-deficient animals. 5. The spectrum of highly purified liver S-adenosylmethionine decarboxylase did not indicate the presence of pyridoxal phosphate. After inactivation of the enzyme by reaction with NaB3H4, radioactivity was incorporated into the enzyme, but was not present as a reduced derivative of pyridoxal phosphate. 6. It is concluded that the decreased concentrations of polyamines in rats fed on a diet containing vitamin B-6 may be due to decreased activity or ornithine decarboxylase or may be caused by an unknown mechanism responding to growth retardation produced by the vitamin deficiency. In either case, measurements of S-adenosylmethionine decarboxylase and ornithine decarboxylase activity under optimum conditions in vitro do not correlate with the polyamine concentrations in vivo.

scholarly journals Redesigning Escherichia coli Metabolism for Anaerobic Production of Isobutanol

2011 ◽  
Vol 77 (14) ◽  
pp. 4894-4904 ◽  
Author(s):  
Cong T. Trinh ◽  
Johnny Li ◽  
Harvey W. Blanch ◽  
Douglas S. Clark
Keyword(s):  
Escherichia Coli ◽  
Anaerobic Growth ◽  
Mode Analysis ◽  
Glycolytic Flux ◽  
Strictly Anaerobic ◽  
Anaerobic Conditions ◽  
Content Type ◽  
E Coli ◽  
Model Predictions ◽  
Chromosomal Genes

ABSTRACTFermentation enables the production of reduced metabolites, such as the biofuels ethanol and butanol, from fermentable sugars. This work demonstrates a general approach for designing and constructing a production host that uses a heterologous pathway as an obligately fermentative pathway to produce reduced metabolites, specifically, the biofuel isobutanol. Elementary mode analysis was applied to design anEscherichia colistrain optimized for isobutanol production under strictly anaerobic conditions. The central metabolism ofE. coliwas decomposed into 38,219 functional, unique, and elementary modes (EMs). The model predictions revealed that during anaerobic growthE. colicannot produce isobutanol as the sole fermentative product. By deleting 7 chromosomal genes, the total 38,219 EMs were constrained to 12 EMs, 6 of which can produce high yields of isobutanol in a range from 0.29 to 0.41 g isobutanol/g glucose under anaerobic conditions. The remaining 6 EMs rely primarily on the pyruvate dehydrogenase enzyme complex (PDHC) and are typically inhibited under anaerobic conditions. The redesignedE. colistrain was constrained to employ the anaerobic isobutanol pathways through deletion of 7 chromosomal genes, addition of 2 heterologous genes, and overexpression of 5 genes. Here we present the design, construction, and characterization of an isobutanol-producingE. colistrain to illustrate the approach. The model predictions are evaluated in relation to experimental data and strategies proposed to improve anaerobic isobutanol production. We also show that the endogenous alcohol/aldehyde dehydrogenase AdhE is the key enzyme responsible for the production of isobutanol and ethanol under anaerobic conditions. The glycolytic flux can be controlled to regulate the ratio of isobutanol to ethanol production.

Inhibitors Influencing Plant Enzymes of the Polyamine Biosynthetic Pathway

1989 ◽  
Vol 44 (1-2) ◽  
pp. 49-54 ◽  
Author(s):  
Marbeth Christ ◽  
Hansruedi Felix ◽  
Jost Harr
Keyword(s):  
Biosynthetic Pathway ◽  
Early Stage ◽  
Arginine Decarboxylase ◽  
Polyamine Biosynthesis ◽  
Polyamine Synthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Stage Of Development ◽  
Decarboxylase Inhibitors ◽  
Plant Enzymes ◽  
To Come

Absract Several enzymes involved in polyamine biosynthesis namely ornithine, arginine and S-adenosylmethionine decarboxylase as well as spermidine synthase, were analyzed in partially purified wheat extracts. For all enzymes effective inhibitors were found. Among them the most interesting was l-aminooxy-3-aminopropane, which inhibited all three decarboxylases. Classical polyamine biosynthesis inhibitors like difluoromethylornithine, difluoromethylarginine. methyl glyoxal bis- (guanylhydrazone) and cyclohexylamine were also inhibitory on plant enzymes. A remarkable difference in the amount of arginine and ornithine decarboxylase existed in wheat. Arginine decarboxylase seems to be more important at least during the early stage of development. Influence of polyamine synthesis inhibitors on polyamine levels is more likely to come from arginine decarboxylase inhibitors. As inhibitors of all essential enzymes involved in plant polyamine biosynthesis were found, the study of the importance of polyamines in plant physiology will be considerably facilitated.

scholarly journals The Disulfide Bond Formation Pathway Is Essential for Anaerobic Growth of Escherichia coli

2017 ◽  
Vol 199 (16) ◽  
Author(s):  
Brian M. Meehan ◽  
Cristina Landeta ◽  
Dana Boyd ◽  
Jonathan Beckwith
Keyword(s):  
Escherichia Coli ◽  
Disulfide Bond ◽  
Bond Formation ◽  
Anaerobic Growth ◽  
Strictly Anaerobic ◽  
Disulfide Bond Formation ◽  
Anaerobic Conditions ◽  
Content Type ◽  
E Coli ◽  
Laboratory Conditions

ABSTRACT Disulfide bonds are critical to the stability and function of many bacterial proteins. In the periplasm of Escherichia coli, intramolecular disulfide bond formation is catalyzed by the two-component disulfide bond forming (DSB) system. Inactivation of the DSB pathway has been shown to lead to a number of pleotropic effects, although cells remain viable under standard laboratory conditions. However, we show here that dsb strains of E. coli reversibly filament under aerobic conditions and fail to grow anaerobically unless a strong oxidant is provided in the growth medium. These findings demonstrate that the background disulfide bond formation necessary to maintain the viability of dsb strains is oxygen dependent. LptD, a key component of the lipopolysaccharide transport system, fails to fold properly in dsb strains exposed to anaerobic conditions, suggesting that these mutants may have defects in outer membrane assembly. We also show that anaerobic growth of dsb mutants can be restored by suppressor mutations in the disulfide bond isomerization system. Overall, our results underscore the importance of proper disulfide bond formation to pathways critical to E. coli viability under conditions where oxygen is limited. IMPORTANCE While the disulfide bond formation (DSB) system of E. coli has been studied for decades and has been shown to play an important role in the proper folding of many proteins, including some associated with virulence, it was considered dispensable for growth under most laboratory conditions. This work represents the first attempt to study the effects of the DSB system under strictly anaerobic conditions, simulating the environment encountered by pathogenic E. coli strains in the human intestinal tract. By demonstrating that the DSB system is essential for growth under such conditions, this work suggests that compounds inhibiting Dsb enzymes might act not only as antivirulents but also as true antibiotics.

scholarly journals Adenovirus type 5 induces progression of quiescent rat cells into S phase without polyamine accumulation.

1982 ◽  
Vol 2 (10) ◽  
pp. 1295-1298 ◽  
Author(s):  
B F Cheetham ◽  
D C Shaw ◽  
A J Bellett
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Thymidine Kinase ◽  
Ornithine Decarboxylase ◽  
Adenovirus Type ◽  
S Phase ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Cellular Dna ◽  
Adenovirus Type 5

Adenovirus type 5 induces cellular DNA synthesis and thymidine kinase in quiescent rat cells but does not induce ornithine decarboxylase. We now show that unlike serum, adenovirus type 5 fails to induce S-adenosylmethionine decarboxylase or polyamine accumulation. The inhibition by methylglyoxal bis(guanylhydrazone) of the induction of thymidine kinase by adenovirus type 5 is probably unrelated to its effects on polyamine biosynthesis. Thus, induction of cellular thymidine kinase and DNA replication by adenovirus type 5 is uncoupled from polyamine accumulation.

scholarly journals Restriction of bacterial growth by inhibition of polyamine biosynthesis by using monofluoromethylornithine, difluoromethylarginine and dicyclohexylammonium sulphate

1982 ◽  
Vol 208 (2) ◽  
pp. 435-441 ◽  
Author(s):  
A J Bitonti ◽  
P P McCann ◽  
A Sjoerdsma
Keyword(s):  
Escherichia Coli ◽  
Ornithine Decarboxylase ◽  
Bacterial Growth ◽  
Active Site ◽  
Bacterial Infections ◽  
Polyamine Biosynthesis ◽  
E Coli ◽  
Subsequent Investigation ◽  
Generation Times ◽  
Viable Approach

Bacterial growth was measurably slowed by a combination of drugs which inhibit polyamine-biosynthetic enzymes. Addition of DL-alpha-monofluoromethylornithine, which was shown to inactivate irreversibly ornithine decarboxylase extracted from Escherichia coli (Ki = 0.36 mM) and Pseudomonas aeruginosa (Ki = 0.30 mM), DL-alpha-difluoromethylarginine and dicyclohexylammonium sulphate to cultures of E. coli or P. aeruginosa resulted in a 40 and 70% increase in generation times (decreased growth rates) respectively, which was completely reversed by the addition of 0.1 mM-putrescine plus 0.1 mM-spermidine to the medium. Decreased intracellular polyamine concentrations correlated with increased generation times; putrescine concentration was decreased by 70% in E. coli and 80% in P. aeruginosa, while spermidine concentration was decreased by 50% in E. coli and 95% in P. aeruginosa. Subsequent investigation of the inactivation of the ornithine decarboxylase by monofluoromethylornithine indicated that it was active-site directed, as the normal substrate ornithine slowed the rate of inhibition. Specific interference with polyamine biosynthesis may be a viable approach to control of some bacterial infections.

Sign in / Sign up

Export Citation Format

Share Document