[The beta-helical domain of bacteriophage T4 controls the folding of the fragment of long tail fibers in a chimeric protein].

The key stage of the infection of the Escherichia coli cell with bacteriophage T4, the binding to the surface of the host cell, is determined by the specificity of the long tail fiber proteins of the phage, in particular, gp37. The assembly and oligomerization of this protein under natural conditions requires the participation of at least two additional protein factors, gp57A and gp38, which strongly hinders the production of the recombinant form of gp37. To overcome this problem, a modern protein engineering strategy was used, which involves the construction of a chimeric protein containing a carrier protein that drives the correct folding of the target protein.

[Pseudomonas aeruginosa bacteriophage SN: 3D-reconstruction of the capsid and identification of surface proteins by electron microscopy].

The virulent P. aeruginosa bacteriophage SN belongs to the PB1-like species of the Myoviridae family. The comparatively small (66391 bp) DNA genome of this phage encodes 89 predicted open reading frames and the proteome involves more than 20 structural proteins.

[Search for destruction factors of bacterial biofilms: comparison of phage properties in a group of Pseudomonas putida bacteriophages and specificity of their halo-formation products].

Comparison of Pseudomonas putida group of phages attributed to five species (af, phi15, phi27, phi2F, and pf16) with their common property of halo-formation (formation of lightening zones) around phage plaques was conducted. The halo around phage plaques appears as a result of reduction or disappearance of bacterial polysaccharide capsules. The concentration of viable bacteria remains unchanged within the halo.

[Study of the diversity in a group of phages of Pseudomonas aeruginosa species PB1 (Myoviridae) and their behavior in adsorbtion-resistant bacterial mutants].

A group of 12 Pseudomonas aeruginosa virulent bacteriophages of different origin scored with regard to the plaque phenotype are assigned to PB1-like species based on the similarity in respect to morphology of particles and high DNA homology. Phages differ in restriction profile and the set of capsid major proteins. For the purpose of studying adsorption properties of these phages, 20 random spontaneous mutants of P.

[Comparison of the genome for phylogenetically related bacteriophages phiKZ and EL of Pseudomonas aeruginosa: evolutionary aspects and minimal genome size].

Bacteriophages of the family Myoviridae represent one of the most widespread domains of the biosphere substantially affecting the ecological balance of microorganisms. Interestingly, sequence analysis of genomic DNAs of large bacteriophages revealed many genes coding for proteins with unknown functions. A new approach is proposed to improve the functional identification of genes.

[Phenogenetic characterization of a group of giant Phi KZ-like bacteriophages of Pseudomonas aeruginosa].

A comparative study was made of a group of Pseudomonas aeruginosa virulent giant DNA bacteriophages similar to phage phi KZ in several genetic and phenotypic properties (particle size, particle morphology, genome size, appearance of negative colonies, high productivity, broad spectrum of lytic activity, ability to overcome the suppressing effect of plasmids, absence of several DNA restriction sites, capability of general transduction, pseudolysogeny). We have recently sequenced the phage phi KZ genome (288,334 bp) [J. Mol.

[Thermostability of bacteriophage T4 fibritin and its deletion mutants].

The thermal stability of a series of recently obtained mutants of fibritin from bacteriophage T4 (a superhelical fibrous homotrimer with parallel-packed subunits each containing 486 amino acid residues) progressively truncated from the subunit N-end was studied during incubation at 40-90 degrees C in the presence of a surfactant (2% SDS). The mutant fibritins, G, B, C, and E, contained 443, 276, 231, and 120 amino acid residues, respectively. One more truncated mutant (fibritin S1, 108 amino acid residues) was obtained.

[Structure and regulation of the assembly of bacteriophage T4 fibrillar proteins. II. Isolation and initial structural characteristics of whiskers].

A procedure for purification of bacteriophage T4 whiskers and it's monomeric subunits--gene product wac--has been developed. We have shown, that the whiskers are composed of two identical copies of gene product wac with molecular weight of 56 kDa each. The dimer of gene product wac is a highly ordered structure and it's length is about 70.

[Structure and regulation of the assembly of bacteriophage T4 fibrillar proteins. I. Isolation and spectral properties of long fibers].

A preparative procedure for purification of the biological active proximal (A) and distal (BC') parts of bacteriophage T4 long-tail fibers is described. Absorption spectra of these proteins in the near ultraviolet region were measured. The absorption coefficients were determined on the basis of the nitrogen content, the absorption coefficient for the A part is epsilon 0.

[Detection of genomic RNA of the hepatitis A virus in clinical samples using the blot hybridization method].

The synthetic oligonucleotide sequence 3'CTCCTCGTACTTTA-5' complementing hepatitis A virus RNA was compared with cDNA probes in identification of viral genomic RNA. The clinical materials from patients in the 1-2 weeks of jaundice were screened. High specificity of the technique was demonstrated.

[A model of the secondary structure and distribution of antigenic determinants in the VP1 protein of hepatitis A virus].

A comparative analysis of amino acid sequence of the proteins VP1 of hepatitis A virus and poliovirus of the 1 type was carried out. A model is proposed of structural organization of VP1 of hepatitis A virus providing the presence of a bilayer core formed by 8 antiparallel beta-strands. Probable candidates for surface antigenic determinants are the amino acid sequences located in unordered fragments of the polypeptide chain (residues 101-106 and 115-125), and alpha-helical region (residues 127-135).

[Structural separation of the functional loci of bacteriophage T4 short fibrillae].

Short-tail fibers (STF) of bacteriophage T4 are a polyfunctional protein. STF appears to be a trimer of gene 12 product. The modified trimers, consisting of fragments of gene 12 product with mol mass 45 and 50 Kd, respectively, were isolated by limited proteolysis with trypsin and papain.

[Isolation of biologically active halves of the long tail fibers and whiskers of bacteriophage T4].

The following substructural elements of bacteriophage T4 have been isolated in homogeneous and biologically active state: the whole long tail fibrils, distal and proximal halves of the long tail fibrils and whiskers. It has been shown that during the infection of Escherichia coli with T4 amber-mutants (defective in the genes coding for heads and tails), the major part of distal and proximal fibril halves found within the cell appears to be unassociated. The interaction of distal and proximal fibril halves with the bacteriophage particle is necessary for the whole tail fibril formation to proceed effectively.