[Nitrogen assimilation enzymes in Bacillus subtilis mutants with hyperproduction of riboflavin].

Three groups of the nitrogen assimilation cycle enzymes (glutamate synthases (GTS), glutamine synthases (GS), and glutamate dehydrogenases (GD)) were studied in Bacillus subtilis strains with hyperproduction of riboflavin (vitamin B2). It was found that in all strains tested activity of GS was virtually the same, activity of GD was absent, and activity of GTS was reduced. In strains 41 and 24, riboflavin producers, activity of GTS was 30-60% the enzyme activity in the original strain (wild-type RosR).

[Pleiotropic function of the phosphoenolpyruvate-dependent phosphotransferase system].

The final Communication III deals with the pleiotropicaction of the phosphotransferase system (PTS) focusing on the below issues related with the bacterial cell: PTS and the nitrous metabolism regulation, virulence, chemotaxis and sporulation. The factor of protein Mlc within the regulation of PTS itself, i.e.

[The pleiotropic function of the phosphoenolpyruvate-dependent phosphotransferase system in bacteria. Communication II].

The structure and function of regulators and anti-terminators is under discussion in gram-positive bacteria. The regulators of lichen and levan operons (LiR and LevR) as well as the implementation of both gram-positive and negative regulations of operons by them are in the focus of attention. Po-independent termination is regarded by the example of the regulatory activity for the utilization systems of glucose (GlcT) beta-glucosides (LicT), sucrose (low-efficiency system SacY-SacX) and of glycerin (GlcP).

[Correlation between activity of the phosphoenol-pyruvate-dependable phosphotransferase system (PTS) and synthesis of adhesion P1 protein in Mycoplasma pneumoniae].

Three isogenous strains M. pneumoniae, i.e.

[Pleiotropic function of phosphoenolpyruvate-dependent phosphotransferase system in bacteria. Report 1].

Modern data (collected mainly in the 1998-2001 studies) about the transport of carbohydrates in bacteria, about the regulation of utilization of sugars via the glycolytic pathway as well as about the regulation of transformation of pyruvat into the products of secondary metabolism and of tricarboxylic acid cycle are presented in the survey. Issues, related with the regulation of synthesis of enzymes involved in the last mentioned process, are discussed in detail. Besides, the key pathways pertaining to the regulation of synthesis and activity of adenylate cyclase; elimination of the inductor in the gram-negative bacteria and entry of phage lambda DNA into E.

[Transketolase mutation in riboflavin-synthesizing strains of Bacillus subtilis].

Unlike its predecessors B. subtilis rosR and 41, riboflavin producing B. subtilis 24 strain does not utilize pentose and gluconate and poorly assimilates glucose.

[Carbohydrate transport systems in Escherichia coli and regulation of catabolism].

The mechanism of carbohydrate uptake in E. coli with involvement of the phosphoenol pyruvate-dependent phosphotransferase system (PTS) is dealt with. The genetic structure of the glucose transport system and fructose operon is given in detail.

[PO-independent termination of transcription of catabolite operons in Escherichia coli and Bacillus subtilis].

The review discusses the Po-independent antitermination in E. coli and B. subtilis.

[Repression of catabolites in gram-positive and gram-negative bacteria].

Analyzes the mechanism of catabolite repression of grampositive and gramnegative bacteria. The role of cyclic adenosine monophosphate and CRP protein, forming a complex, is shown. Contribution of ATP kinase to manifestation of the catabolic repression phenomenon in grampositive bacteria is discussed.

[Isolation and properties of mutants devoid of pseudo-HPr activity of the fructose transfer system in Escherichia coli K12].

Mutants without pseudo-HPr activity intrinsic to the H domain of the FruB protein were obtained in Escherichia coli K12 through insertional mutagenesis by means of the MudIlac phage and TnPhoA transposon. For isolating these mutants, double mutants of enteric bacterium (ptsH fruR of ptsH fruS) were used as original strains. These double mutants were inactive with respect to the total HPr protein of the phosphoenolpyruvate-carbohydrate phosphotransferase system and could not provide constitutive synthesis of fructose-specific proteins of this system.

[Determination of the direction of transcription of Escherichia coli K-12 structural genes of the fructose regulon in vivo].

The direction of transcription of specific components of the fructose phosphotransferase system, the fruA, fruK, and fruB genes, was determined in vivo by plasmid F'ts1141ac. Transcription from each of these genes was shown to run in the same direction, counterclockwise with respect to the E. coli chromosomal map.

[Role of fructose-1-phosphate kinase in expression of PEP-synthase in Escherichia coli K-12].

Mutational damage of the fruK gene coding for fructose-1-phosphate kinase leads to 2-6-fold (depending on the strain) decrease in FEP synthase activity in Escherichia coli. The fruK mutants were unable to utilize lactate as well as fructose and fructose-1-phosphate, acquiring, in addition, sensitivity to mannose in their growth medium. Reversions back to FruK+ phenotype or introduction of an intact fruK allele resulted in restoration of both FEP synthase activity and the ability to grow on lactate.

[Uncoupling expression of genes coding for the synthesis of proteins involved in transport and utilization of fructose in Escherichia coli K-12].

A novel mutation fruS localised in the fru operon has been obtained. The mutation uncouples expression of genes determining fructose specific uptake and utilization. In the fruS bacteria fruA and fruF genes (coding for enzyme II and FPr, respectively) become constitutive, while the fruK gene (responsible for fructose-1-phosphate kinase synthesis) remains inducible.

[Specific systems of phosphoenolpyruvate-dependent transport of carbohydrates in enterobacteria].

The data of foreign researchers on the specific phosphoenolpyruvate-dependent phosphotransferase systems (PTS) transporting mannose, aminosugars and natural beta-glucosides are reviewed. The genetical, biochemical and molecular biological aspects of the corresponding PTS functioning are presented. The role of those PTS in bacteriophage lambda DNA penetration into the cell, in streptozotocin resistance is discussed.

[Transport of six-atom alcohols by enterobacteria].

The data obtained by foreign researchers on the transport of hexitols mannitol, galactitol and glucitol in enterobacteria are presented in the review. The genetical, biochemical and molecular biological aspects of functioning of the specific phosphoenolpyruvate-dependent phosphotransferase systems that transport the above mentioned polyols are discussed as well as the role of the components of glucitol transport system in gluconeogenesis regulation.

Bacteriophages of Bordetella sp.: features of lysogeny and conversion.

It has been the purpose of this paper to study molecular-biological features of the Bordetella bacteriophage interaction with the host cell during lysogeny and conversion as well as to determine the degree of homology between genomes of homologous and heterologous bacteriophages. Genomes of bacteriophages from B. pertussis 134, 41405 and B.

[Detection of the gene sequences of the leukocytosis (lymphocytosis)-stimulating factor of Bordetella pertussis in Bordetella parapertussis and Bordetella bronchiseptica by using molecular hybridization].

The 4.7 Kb EcoRI-fragment of phase I B. pertussis 475 (serovar 1.

[Cloning and gene expression of the leukocytosis (lymphocytosis) stimulating factor of Bordatella pertussis in Escherichia coli by bringing the PT genes close to the lactose promoter of plasmid pUC19].

The 4.7 Kb EcoRI-fragment of phase I B. pertussis 475 (serovar 1.

[Mutation fruB in the fructose regulon affecting beta-galactosidase synthesis and adenylate cyclase activity of E. coli K12].

Escherichia coli mutant devoid of fructosespecific factor III (factor IIIfru) of phosphoenolpyruvate (PEP) carbohydrate phosphotransferase system was isolated. The mutation fruB was localized on 46 min of chromosomal map of Escherichia coli in the fru-operon region. The mutant bacteria are unable to accumulate fructose.

[Identification of protein products of the operon for leukocytosis (lymphocytosis)-stimulating factor from Bordetella pertussis cloned in Escherichia coli].

The hybrid plasmid pRH119 was constructed on the basis of vector plasmid pUC19 and shown to carry Bordetella pertussis PT operon in the same transcriptional orientation with the lac-promoter of the vector plasmid. Expression of PT genes in E. coli cells harbouring pRH119 was not registered.

[Analysis of mutations affecting the expression of catabolite-sensitive operons in Escherichia coli K12 mutants defective in the HPr-component of the carbohydrate transport system].

Expression of catabolite-sensitive operons in mutants devoid of HPr (a component of the glucose transport system) is severely repressed. ptsH mutants do not utilize substrates of the phosphoenolpyruvate: carbohydrate system (PTS) and many other sugars. Analysis of mutations suppressing the effect of the delta ptsH mutation revealed a new class of reversions which restore the growth of bacteria on different substrates.

[Cloning of the genes of hemolytic factors of Bordetella pertussis in Escherichia coli].

The gene library of B. pertussis strain No. 475 (serovar 1.