Recalibrated linkage map of Escherichia coli K-12.

Functions of the gene products of Escherichia coli.

INTRODUCTION ................ ROLE OF CYCLIC AMP IN REGULATION OF GENE EXPRESSION .......... A Positive Element in Gene Expression ...................................... CRP .......................... :........................................... Direct stimulation of gene expression ...................................... Possible Role As a Negative Element ......................................... Does Cyclic AMP Rave Other Actions in E. co .............................. OPERON ACTIVATION BY CYCLIC AMP .................................... Genetic analysis of the lac promoter ....................................... CONTROL OF CYCLIC AMP LEVELS ........................................ Adenylate Cyclase ........................................................... Cyclic AMP Phosphodiesterase ...................................... Cyclic AMP Release ......................................................... Rate of Cyclic AMP Synthesis ............................................... CYCLIC AMP RECEPTOR PROTEIN ........................................ Physical properties of CRP ................................................ Cyclic AMP binding .... Promoter-specific DNAbinding. Effects of cyclic AMP on CRP structure .................................... CYCLIC AMP AND BACTERIOPHAGE A ...................................... CYCLIC GMP ................................................................ CONCLUSION ................................................................ LITERATURE CITED ........................................................

https://mmbr.asm.org/content/mmbr/40/3/527.full.pdf

Cyclic adenosine 5'-monophosphate in Escherichia coli.

Genetic studies show that Escherichia coli has three enzymes capable of phosphorylating glucose: soluble adenosine 5'-triphosphate-dependent glucokinase, which plays only a minor role in glucose metabolism; an enzyme II, called glucosephosphotransferase, with high specificity for the D-glucose configuration; and another enzyme II, called mannosephosphotransferase, with broader specificity. The former enzyme II is active on glucose and methyl-alpha-glucopyranoside, whereas the latter is active on D-glucose, D-mannose, 2-deoxy-D-glucose, D-glucosamine, and D-mannosamine. Mutations leading to loss of glucosephosphotransferase activity and designated by the symbol gpt are between the purB and pyrC markers in a locus previously called cat. The locus of mutations to loss of mannosephosphotransferase, mpt, is between the eda and fadD genes. Mutations to loss of glucokinase, glk, are between the ptsI and dsd genes.

Phosphorylation of D-glucose in Escherichia coli mutants defective in glucosephosphotransferase, mannosephosphotransferase, and glucokinase.

A new metabolic pathway has been created in the microorganism Erwinia herbicola that gives it the ability to produce 2-keto-L-gulonic acid, an important intermediate in the synthesis of L-ascorbic acid. Initially, a Corynebacterium enzyme that could stereoselectively reduce 2,5-diketo-D-gluconic acid to 2-keto-L-gulonic acid was identified and purified. DNA probes based on amino acid sequence information from 2,5-diketo-D-gluconic acid reductase were then used to isolate the gene for this enzyme from a Corynebacterium genomic library. The 2,5-diketo-D-gluconic acid reductase coding region was fused to the Escherichia coli trp promoter and a synthetic ribosome binding site and was then introduced into E. herbicola on a multicopy plasmid. Erwinia herbicola naturally produces 2,5-diketo-D-gluconic acid via glucose oxidation, and when recombinant cells expressing the plasmid-encoded reductase were grown in the presence of glucose, 2-keto-L-gulonic acid was made and released into the culture medium. The data demonstrate the feasibility of creating novel in vivo routes for the synthesis of important specialty chemicals by combining useful metabolic traits from diverse sources in a single organism.

https://science.sciencemag.org/content/sci/230/4722/144.full.pdf

Production of 2-Keto-L-Gulonate, an Intermediate in L-Ascorbate Synthesis, by a Genetically Modified Erwinia herbicola

[Study of the common degradative pathway of hexuronates in Escherichia coli K 12. Purification, properties and individuality of 2-keto-3-deoxy-D-gluconnokinase].

We have presented kinetic evidence for the occurrence in Escherichia coli K 12 of an active transport system responsible for 2-keto-3-deoxy-d-gluconate uptake. It has been studied in constitutive strains PK4 and CAK 101 since it is completely cryptic in the wild-type strain.



1
The accumulation is temperature-dependent, coupled to electron and energy-yielding reactions, and is inhibited by thiol reagents.

2
2-Keto-3-deoxy-d-gluconate is not transported through the phospho-enolpyruvate-transferase system.

3
Entry reaction displays saturation kinetics obeying the Michaelis-Menten laws. The Km value has been found to be 0.25 ± 0.05 mM (at 30 °C and pH 7.0), by measuring initial rates of entrance as well as steady-state levels. Both the operator-constitutive PK4 strain and the regulator-constitutive CAK101 strain exhibit the same affinity but apparent V are 10 and 20 nmol × mg-1× min-1, respectively.

4
The 2-keto-3-deoxy-d-gluconate permeation system is endogenously induced in a strain lacking 2-keto-3-deoxy-d-gluconate kinase, when grown on any intermediary product of the hexuronide catabolic pathway, able to enter the cell and anterior to 2-keto-3-deoxy-d-gluconate in the sequence. We presented further evidence making it very likely that 2-keto-3-deoxy-d-gluconate itself is the true inducer.

5
The constitutive synthesis of the transport system is sensitive to the catabolite repression exerted by glucose and pyruvate.

6
By testing a wide number of sugars and derivatives as possible substrates, only d-glucuronate is a strictly competitive inhibitor (Ki= 1.5 mM). Since a specific hexuronate permease has been described elsewhere, we were led to demonstrate that d-glucuronate could be taken up through both its own specific system with high affinity and through the 2-keto-3-deoxy-d-gluconate specific system with lower affinity.

7
The exit reaction rate is first oder with respect to internal concentration, temperature-dependent (exit rate constant kex is 0.0180 min-1 at 30 °C) but is not carrier-mediated.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1973.tb02917.x

A transport system for 2-keto-3-deoxy-D-gluconate uptake in Escherichia coli K12. Biochemical and physiological studies in whole cells.

We have isolated mutants unable to utilize any of the following carbon sources: D-glucuronate, D-galacturonate, and D-gluconate. During the metabolism of each of these substrates, these mutants accumulate 2-keto-3-deoxy-6-P-gluconate; they were subsequently found to be deficient for the enzyme: 2-keto-3-deoxy-6-P-gluconate aldolase. This deficiency results in an inhibition of growth on various carbonsources when a hexuronate or gluconate is present in the medium.

[Map location of 2-keto-3-deoxy-6-P-gluconate aldolase negative mutations in E. coli K12].

KDG which is not utilized by E. coli wild type is metabolized in spontaneous mutants as a unique carbon source via a specific transport system, a KDG-kinase and a KDPG-aldolase. A preliminary note has shown that these 3 enzymes depending on 3 separate operons are under the negative control of the kdg R product. Physiological as well as genetic evidences are presented in this paper dealing with occurence of a KDG specific transport system in the wild type. Constitutive (kdg P
c) and negative (kdg T
−) permease mutants have been isolated and the mutations mapped within the rhamet B region. Mating and transduction experiments have established the following order: rha D-(kdg P, kdg T)-pfk-glp K-met B-arg (HE). On the basis of indirect arguments, it is suggested that the constitutive (kdg P
c) and negative (kdg T
−) mutations, which have been found to be strongly linked, affect respectively the operator site and a structural gene needed for the KDG transport system. The kdg P-kdg T-glp K order defined by conjugation gives the transcriptional direction of this kdg T operon.

Jacques M. Pouysségur

Papers

[Study of the common degradative pathway of hexuronates in Escherichia coli K 12. Purification, properties and individuality of 2-keto-3-deoxy-D-gluconnokinase].

A transport system for 2-keto-3-deoxy-D-gluconate uptake in Escherichia coli K12. Biochemical and physiological studies in whole cells.

[Map location of 2-keto-3-deoxy-6-P-gluconate aldolase negative mutations in E. coli K12].

Système de transport du 2-céto-3-désoxy-gluconate chez E. coli K12: localisation d'un gène de structure et de son opérateur

Le métabolisme des hexuronides et des hexuronates chez Escherichia coli K 12: Aspects physiologiques et génétiques de sa régulation