Lidia Kurochkina - Academia.edu (original) (raw)
Papers by Lidia Kurochkina
The Biochemical journal, Jan 31, 2016
Recently, we discovered and studied the first virus-encoded chaperonin of bacteriophage EL Pseudo... more Recently, we discovered and studied the first virus-encoded chaperonin of bacteriophage EL Pseudomonas aeruginosa, gene product (gp) 146. In the present work, we performed bioinformatics analysis of currently predicted GroEL-like proteins encoded by phage genomes in comparison with cellular and mitochondrial chaperonins. Putative phage chaperonins share a low similarity and do not form a monophyletic group; nevertheless, they are closer to bacterial chaperonins in the phylogenetic tree. Experimental investigation of putative GroEL-like chaperonin proteins has been continued by physicochemical and functional characterization of gp246 encoded by the genome of Pseudomonas fluorescens bacteriophage OBP. Unlike the more usual double-ring architecture of chaperonins, including the EL gp146, the recombinant gp246 produced by E. coli cells has been purified as a single heptameric ring. It possesses an ATPase activity and does not require a co-chaperonin for its functioning. In vitro experim...
Virology, 2003
The complete DNA sequence of a new lytic T7-like bacteriophage φKMV is presented. It is the first... more The complete DNA sequence of a new lytic T7-like bacteriophage φKMV is presented. It is the first genome sequence of a member of the Podoviridae that infects Pseudomonas aeruginosa. The linear G + C-rich (62.3%) double-stranded DNA genome of 42,519 bp has direct terminal repeats of 414 bp and contains 48 open reading frames that are all transcribed from the same strand. Despite absence of homology at the DNA level, 11 of the 48 φKMV-encoded putative proteins show sequence similarity to known T7-type phage proteins. Eighteen open reading frame products have been assigned, including an RNA polymerase, proteins involved in DNA replication, as well as structural, phage maturation, and lysis proteins. Surprisingly, the major capsid protein completely lacks sequence homology to any known protein. Also, the strong virulence toward many clinical P. aeruginosa isolates and a short replication time make φKMV attractive for phage therapy or a potential source for antimicrobial proteins.
J Mol Biol, 2005
The three-dimensional structure of the Pseudomonas aeruginosa bacteriophage ϕKZ head has been det... more The three-dimensional structure of the Pseudomonas aeruginosa bacteriophage ϕKZ head has been determined by cryo-electron microscopy and image reconstruction to 18 Å resolution. The head has icosahedral symmetry measuring 1455 Å in diameter along 5-fold axes and a unique portal vertex to which is attached an approximately 1800 Å-long contractile tail. The 65 kDa major capsid protein, gp120, is organized into a surface lattice of hexamers, with T=27 triangulation. The shape and size of the hexamers is similar to the hexameric building blocks of the bacteriophages T4, ϕ29, P22, and HK97. Pentameric vertices of the capsid are occupied by complexes composed of several special vertex proteins. The double-stranded genomic DNA is packaged into a highly condensed series of layers, separated by 24 Å, that follow the contour of the inner wall of the capsid.
Biokhimii͡a (Moscow, Russia)
The effect of UV light (lambda = 254 nm) on calf thymus DNP at low ionic strengths was studied. I... more The effect of UV light (lambda = 254 nm) on calf thymus DNP at low ionic strengths was studied. It was found that at the irradiation doses used the protein in the DNA-protein complex increases as the irradiation dose rises. Thermal treatment and acid hydrolysis resulted in a predominant release of histones H3 and H1 from the complex. Data from liquid high performance chromatography, amino acid analysis, thin-layer chromatography point to the induction by UV-light of a thymine-lysine bond, whose formation involves DNA thymines and histone lysine residues, predominantly H3 and H1 fractions.
Biokhimii͡a (Moscow, Russia)
A thymine-modified derivative of histone H3 formed as a result of thermal treatment of UV-irradia... more A thymine-modified derivative of histone H3 formed as a result of thermal treatment of UV-irradiated (lambda = 254 nm) solution of deoxyribonucleoprotein from calf thymus at low ionic strength was isolated. The peptides obtained by tryptic hydrolysis of modified histone H3 were separated by high pressure liquid chromatography. The amino acid sequence of the peptide containing a lysine residue with covalently linked thymine was determined by the Edman method. It was found that Lys localized at the N-terminus of the histone H3 molecule interacts with DNA within the composition of the deoxyribonucleoprotein.
Nauchnye doklady vyssheĭ shkoly. Biologicheskie nauki
A method of radioiodination to high specific activity by Bolton Hunter reagent of fixed and stain... more A method of radioiodination to high specific activity by Bolton Hunter reagent of fixed and stained histones in polyacrylamide gel is described. The comparative peptide maps of the histones H1 and H3, labelled in solution and the gel are presented.
Biokhimii͡a (Moscow, Russia)
The interaction between total histone and deoxyribonucleoprotein (DNP) preparations from calf thy... more The interaction between total histone and deoxyribonucleoprotein (DNP) preparations from calf thymus with mercury-containing nitroxyl radicals in low ionic strength solutions, 2 M NaCl and urea was investigated. It was found that the label is rapidly incorporated into the SH-groups of histone H3 to produce characteristic EPR signals. Titration of SH-groups within DNP demonstrated that in low ionic strength solutions only one SH-group (presumably, the SH-group of the cysteine residue in position 110) is accessible to the reagents. After dissociation by 2 M NaCl, two SH-groups become titrable; however, the EPR spectra point to differences in the conformational state of these two groups. In 4 M urea, these differences are compensated for by structural disintegration. The spin labels may be used for the analysis of SH-groups under different conditions and at different functional states of nucleoproteins.
Biokhimii͡a (Moscow, Russia)
UV-irradiated DNP was digested by trypsin to cleave histones, and a crosslinked DNA-peptide compl... more UV-irradiated DNP was digested by trypsin to cleave histones, and a crosslinked DNA-peptide complex was isolated. The globular domain of histone HI was found to be linked to DNA. The resistance of the globule to trypsinolysis is discussed with regard to chromatin structure.
Biokhimii͡a (Moscow, Russia)
UV-Irradiation (lambda = 254 nm) of Hela cells in the monolayer causes a dose-dependent formation... more UV-Irradiation (lambda = 254 nm) of Hela cells in the monolayer causes a dose-dependent formation of DNA-protein crosslinks (DPC). The time-dependent protein increase unaccompanied by a change in the complex yield was observed for the fraction of the DNA-protein complex passing into the aqueous phase by phenol extraction, when the cells were transferred to a fresh culture medium after UV-irradiation. These data suggest that DPC do not repair, while DNA or the protein within the complex can firmly bind additional quantity of protein during the post-irradiation period.
Biochemistry (Moscow)
ABSTRACT
Bioorganicheskaia khimiia
The virulent P. aeruginosa bacteriophage SN belongs to the PB1-like species of the Myoviridae fam... more 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. A 3D model of the phage capsid to approximately 18 A resolution reveals certain peculiarities of capsomer structure typical of only this bacteriophage species. In the present work recombinant structural proteins SN gp22 and gp29 were expressed and purified; and specific polyclonal antibodies were obtained. Immune-electron microscopy of purified phage SN using secondary gold-conjugated antibodies has revealed that gp29 forms a phage sheath, and gp22 decorates the capsid. Precise identification of multicopy major capsid proteins is essential for subsequent construction of gene-engineered phages bearing non-native peptides on their surfaces (phage display).
Biochemistry (Moscow)
Protein folding in the cell is controlled at the levels of translation and post-translational mod... more Protein folding in the cell is controlled at the levels of translation and post-translational modification, depends on a number of conserved proteins known as chaperones, and is catalyzed by specific enzymes, such as protein disulfide isomerase and peptidyl prolyl cis-trans isomerase. The chaperones stabilize folding intermediates and participate in assembly and disaggregation of supramolecular structures. Bacteriophage T4 is an especially convenient system for studying of protein folding mechanisms, since its genome encodes several virus-specific chaperones. In this review, the chaperones of phage T4 that take part in capsid formation (gp31 and gp40) and in folding and assembly of virion tail fibers (gp38, gp57A) have been considered. Protein encoded by gene 31 completely substitutes co-chaperonin GroES of the host cell in folding of the major capsid protein, gp23, aided by chaperonin GroEL. The product of gene 40, which is homologous to analogs of eukaryotic GroEL and peptidyl pro...
Biochemistry (Moscow), 2015
Genome announcements, 2014
The novel giant Pseudomonas aeruginosa bacteriophage PaBG was isolated from a water sample of the... more The novel giant Pseudomonas aeruginosa bacteriophage PaBG was isolated from a water sample of the ultrafreshwater Lake Baikal. We report the complete genome sequence of this Myoviridae bacteriophage, comprising 258,139 bp of double-stranded DNA containing 308 predicted open reading frames.
Journal of virology, 2012
Chaperonins promote protein folding in vivo and are ubiquitously found in bacteria, archaea, and ... more Chaperonins promote protein folding in vivo and are ubiquitously found in bacteria, archaea, and eukaryotes. The first viral chaperonin GroEL ortholog, gene product 146 (gp146), whose gene was earlier identified in the genome of bacteriophage EL, has been shown to be synthesized during phage propagation in Pseudomonas aeruginosa cells. The recombinant gp146 has been expressed in Escherichia coli and characterized by different physicochemical methods for the first time. Using serum against the recombinant protein, gp146's native substrate, the phage endolysin gp188, has been immunoprecipitated from the lysate of EL-infected bacteria and identified by mass spectrometry. In vitro experiments have shown that gp146 has a protective effect against endolysin thermal inactivation and aggregation, providing evidence of its chaperonin function. The phage chaperonin has been found to have the architecture and some properties similar to those of GroEL but not to require cochaperonin for its...
Bioorganicheskaia khimiia
The virulent P. aeruginosa bacteriophage SN belongs to the PB1-like species of the Myoviridae fam... more 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. A 3D model of the phage capsid to approximately 18 A resolution reveals certain peculiarities of capsomer structure typical of only this bacteriophage species. In the present work recombinant structural proteins SN gp22 and gp29 were expressed and purified; and specific polyclonal antibodies were obtained. Immune-electron microscopy of purified phage SN using secondary gold-conjugated antibodies has revealed that gp29 forms a phage sheath, and gp22 decorates the capsid. Precise identification of multicopy major capsid proteins is essential for subsequent construction of gene-engineered phages bearing non-native peptides on their surfaces (phage display).
Biochemistry. Biokhimii͡a, 2002
Gene product 18 (gp18, 659 amino acids) forms bacteriophage T4 contractile tail sheath. Recombina... more Gene product 18 (gp18, 659 amino acids) forms bacteriophage T4 contractile tail sheath. Recombinant protein assembles into different length polysheaths during expression in the cell, which complicates the preparation of protein crystals for its spatial structure determination. To design soluble monomeric gp18 mutants unable to form polysheaths and useful for crystallization, we have used Bal31 nuclease for generation deletions inside gene 18 encoding the Ile507-Gly530 region. Small deletions in the region of Ile507-Ile522 do not affect the protein assembly into polysheaths. Protein synthesis termination occurs because of reading frame failure in the location of deletions. Some fragments of gp18 containing short pseudo-accidental sequence in the C-terminal, while being soluble, have lost the ability for polysheath assembly. For the first time we succeeded in obtaining crystals of a soluble gp18 fragment containing 510 amino acids which, according to trypsin resistance, is similar to ...
Genetika, 2002
A comparative study was made of a group of Pseudomonas aeruginosa virulent giant DNA bacteriophag... more 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. Biol., 2002, vol. 317, pp. 1-19]. By DNA homology, the phages were assigned to three species (represented by phage phi KZ, Lin68, and EL, respectively) and two new genera (phi KZ and EL). Restriction enzyme analysis revealed the mosaic genome structure in four phages of the phi KZ species (phi KZ, Lin21, NN, and PTB80) and two phages of the EL species (EL and RU). Comparisons with respect to phage particle size, number of structural proteins, and the N-terminal se...
The Biochemical journal, Jan 31, 2016
Recently, we discovered and studied the first virus-encoded chaperonin of bacteriophage EL Pseudo... more Recently, we discovered and studied the first virus-encoded chaperonin of bacteriophage EL Pseudomonas aeruginosa, gene product (gp) 146. In the present work, we performed bioinformatics analysis of currently predicted GroEL-like proteins encoded by phage genomes in comparison with cellular and mitochondrial chaperonins. Putative phage chaperonins share a low similarity and do not form a monophyletic group; nevertheless, they are closer to bacterial chaperonins in the phylogenetic tree. Experimental investigation of putative GroEL-like chaperonin proteins has been continued by physicochemical and functional characterization of gp246 encoded by the genome of Pseudomonas fluorescens bacteriophage OBP. Unlike the more usual double-ring architecture of chaperonins, including the EL gp146, the recombinant gp246 produced by E. coli cells has been purified as a single heptameric ring. It possesses an ATPase activity and does not require a co-chaperonin for its functioning. In vitro experim...
Virology, 2003
The complete DNA sequence of a new lytic T7-like bacteriophage φKMV is presented. It is the first... more The complete DNA sequence of a new lytic T7-like bacteriophage φKMV is presented. It is the first genome sequence of a member of the Podoviridae that infects Pseudomonas aeruginosa. The linear G + C-rich (62.3%) double-stranded DNA genome of 42,519 bp has direct terminal repeats of 414 bp and contains 48 open reading frames that are all transcribed from the same strand. Despite absence of homology at the DNA level, 11 of the 48 φKMV-encoded putative proteins show sequence similarity to known T7-type phage proteins. Eighteen open reading frame products have been assigned, including an RNA polymerase, proteins involved in DNA replication, as well as structural, phage maturation, and lysis proteins. Surprisingly, the major capsid protein completely lacks sequence homology to any known protein. Also, the strong virulence toward many clinical P. aeruginosa isolates and a short replication time make φKMV attractive for phage therapy or a potential source for antimicrobial proteins.
J Mol Biol, 2005
The three-dimensional structure of the Pseudomonas aeruginosa bacteriophage ϕKZ head has been det... more The three-dimensional structure of the Pseudomonas aeruginosa bacteriophage ϕKZ head has been determined by cryo-electron microscopy and image reconstruction to 18 Å resolution. The head has icosahedral symmetry measuring 1455 Å in diameter along 5-fold axes and a unique portal vertex to which is attached an approximately 1800 Å-long contractile tail. The 65 kDa major capsid protein, gp120, is organized into a surface lattice of hexamers, with T=27 triangulation. The shape and size of the hexamers is similar to the hexameric building blocks of the bacteriophages T4, ϕ29, P22, and HK97. Pentameric vertices of the capsid are occupied by complexes composed of several special vertex proteins. The double-stranded genomic DNA is packaged into a highly condensed series of layers, separated by 24 Å, that follow the contour of the inner wall of the capsid.
Biokhimii͡a (Moscow, Russia)
The effect of UV light (lambda = 254 nm) on calf thymus DNP at low ionic strengths was studied. I... more The effect of UV light (lambda = 254 nm) on calf thymus DNP at low ionic strengths was studied. It was found that at the irradiation doses used the protein in the DNA-protein complex increases as the irradiation dose rises. Thermal treatment and acid hydrolysis resulted in a predominant release of histones H3 and H1 from the complex. Data from liquid high performance chromatography, amino acid analysis, thin-layer chromatography point to the induction by UV-light of a thymine-lysine bond, whose formation involves DNA thymines and histone lysine residues, predominantly H3 and H1 fractions.
Biokhimii͡a (Moscow, Russia)
A thymine-modified derivative of histone H3 formed as a result of thermal treatment of UV-irradia... more A thymine-modified derivative of histone H3 formed as a result of thermal treatment of UV-irradiated (lambda = 254 nm) solution of deoxyribonucleoprotein from calf thymus at low ionic strength was isolated. The peptides obtained by tryptic hydrolysis of modified histone H3 were separated by high pressure liquid chromatography. The amino acid sequence of the peptide containing a lysine residue with covalently linked thymine was determined by the Edman method. It was found that Lys localized at the N-terminus of the histone H3 molecule interacts with DNA within the composition of the deoxyribonucleoprotein.
Nauchnye doklady vyssheĭ shkoly. Biologicheskie nauki
A method of radioiodination to high specific activity by Bolton Hunter reagent of fixed and stain... more A method of radioiodination to high specific activity by Bolton Hunter reagent of fixed and stained histones in polyacrylamide gel is described. The comparative peptide maps of the histones H1 and H3, labelled in solution and the gel are presented.
Biokhimii͡a (Moscow, Russia)
The interaction between total histone and deoxyribonucleoprotein (DNP) preparations from calf thy... more The interaction between total histone and deoxyribonucleoprotein (DNP) preparations from calf thymus with mercury-containing nitroxyl radicals in low ionic strength solutions, 2 M NaCl and urea was investigated. It was found that the label is rapidly incorporated into the SH-groups of histone H3 to produce characteristic EPR signals. Titration of SH-groups within DNP demonstrated that in low ionic strength solutions only one SH-group (presumably, the SH-group of the cysteine residue in position 110) is accessible to the reagents. After dissociation by 2 M NaCl, two SH-groups become titrable; however, the EPR spectra point to differences in the conformational state of these two groups. In 4 M urea, these differences are compensated for by structural disintegration. The spin labels may be used for the analysis of SH-groups under different conditions and at different functional states of nucleoproteins.
Biokhimii͡a (Moscow, Russia)
UV-irradiated DNP was digested by trypsin to cleave histones, and a crosslinked DNA-peptide compl... more UV-irradiated DNP was digested by trypsin to cleave histones, and a crosslinked DNA-peptide complex was isolated. The globular domain of histone HI was found to be linked to DNA. The resistance of the globule to trypsinolysis is discussed with regard to chromatin structure.
Biokhimii͡a (Moscow, Russia)
UV-Irradiation (lambda = 254 nm) of Hela cells in the monolayer causes a dose-dependent formation... more UV-Irradiation (lambda = 254 nm) of Hela cells in the monolayer causes a dose-dependent formation of DNA-protein crosslinks (DPC). The time-dependent protein increase unaccompanied by a change in the complex yield was observed for the fraction of the DNA-protein complex passing into the aqueous phase by phenol extraction, when the cells were transferred to a fresh culture medium after UV-irradiation. These data suggest that DPC do not repair, while DNA or the protein within the complex can firmly bind additional quantity of protein during the post-irradiation period.
Biochemistry (Moscow)
ABSTRACT
Bioorganicheskaia khimiia
The virulent P. aeruginosa bacteriophage SN belongs to the PB1-like species of the Myoviridae fam... more 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. A 3D model of the phage capsid to approximately 18 A resolution reveals certain peculiarities of capsomer structure typical of only this bacteriophage species. In the present work recombinant structural proteins SN gp22 and gp29 were expressed and purified; and specific polyclonal antibodies were obtained. Immune-electron microscopy of purified phage SN using secondary gold-conjugated antibodies has revealed that gp29 forms a phage sheath, and gp22 decorates the capsid. Precise identification of multicopy major capsid proteins is essential for subsequent construction of gene-engineered phages bearing non-native peptides on their surfaces (phage display).
Biochemistry (Moscow)
Protein folding in the cell is controlled at the levels of translation and post-translational mod... more Protein folding in the cell is controlled at the levels of translation and post-translational modification, depends on a number of conserved proteins known as chaperones, and is catalyzed by specific enzymes, such as protein disulfide isomerase and peptidyl prolyl cis-trans isomerase. The chaperones stabilize folding intermediates and participate in assembly and disaggregation of supramolecular structures. Bacteriophage T4 is an especially convenient system for studying of protein folding mechanisms, since its genome encodes several virus-specific chaperones. In this review, the chaperones of phage T4 that take part in capsid formation (gp31 and gp40) and in folding and assembly of virion tail fibers (gp38, gp57A) have been considered. Protein encoded by gene 31 completely substitutes co-chaperonin GroES of the host cell in folding of the major capsid protein, gp23, aided by chaperonin GroEL. The product of gene 40, which is homologous to analogs of eukaryotic GroEL and peptidyl pro...
Biochemistry (Moscow), 2015
Genome announcements, 2014
The novel giant Pseudomonas aeruginosa bacteriophage PaBG was isolated from a water sample of the... more The novel giant Pseudomonas aeruginosa bacteriophage PaBG was isolated from a water sample of the ultrafreshwater Lake Baikal. We report the complete genome sequence of this Myoviridae bacteriophage, comprising 258,139 bp of double-stranded DNA containing 308 predicted open reading frames.
Journal of virology, 2012
Chaperonins promote protein folding in vivo and are ubiquitously found in bacteria, archaea, and ... more Chaperonins promote protein folding in vivo and are ubiquitously found in bacteria, archaea, and eukaryotes. The first viral chaperonin GroEL ortholog, gene product 146 (gp146), whose gene was earlier identified in the genome of bacteriophage EL, has been shown to be synthesized during phage propagation in Pseudomonas aeruginosa cells. The recombinant gp146 has been expressed in Escherichia coli and characterized by different physicochemical methods for the first time. Using serum against the recombinant protein, gp146's native substrate, the phage endolysin gp188, has been immunoprecipitated from the lysate of EL-infected bacteria and identified by mass spectrometry. In vitro experiments have shown that gp146 has a protective effect against endolysin thermal inactivation and aggregation, providing evidence of its chaperonin function. The phage chaperonin has been found to have the architecture and some properties similar to those of GroEL but not to require cochaperonin for its...
Bioorganicheskaia khimiia
The virulent P. aeruginosa bacteriophage SN belongs to the PB1-like species of the Myoviridae fam... more 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. A 3D model of the phage capsid to approximately 18 A resolution reveals certain peculiarities of capsomer structure typical of only this bacteriophage species. In the present work recombinant structural proteins SN gp22 and gp29 were expressed and purified; and specific polyclonal antibodies were obtained. Immune-electron microscopy of purified phage SN using secondary gold-conjugated antibodies has revealed that gp29 forms a phage sheath, and gp22 decorates the capsid. Precise identification of multicopy major capsid proteins is essential for subsequent construction of gene-engineered phages bearing non-native peptides on their surfaces (phage display).
Biochemistry. Biokhimii͡a, 2002
Gene product 18 (gp18, 659 amino acids) forms bacteriophage T4 contractile tail sheath. Recombina... more Gene product 18 (gp18, 659 amino acids) forms bacteriophage T4 contractile tail sheath. Recombinant protein assembles into different length polysheaths during expression in the cell, which complicates the preparation of protein crystals for its spatial structure determination. To design soluble monomeric gp18 mutants unable to form polysheaths and useful for crystallization, we have used Bal31 nuclease for generation deletions inside gene 18 encoding the Ile507-Gly530 region. Small deletions in the region of Ile507-Ile522 do not affect the protein assembly into polysheaths. Protein synthesis termination occurs because of reading frame failure in the location of deletions. Some fragments of gp18 containing short pseudo-accidental sequence in the C-terminal, while being soluble, have lost the ability for polysheath assembly. For the first time we succeeded in obtaining crystals of a soluble gp18 fragment containing 510 amino acids which, according to trypsin resistance, is similar to ...
Genetika, 2002
A comparative study was made of a group of Pseudomonas aeruginosa virulent giant DNA bacteriophag... more 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. Biol., 2002, vol. 317, pp. 1-19]. By DNA homology, the phages were assigned to three species (represented by phage phi KZ, Lin68, and EL, respectively) and two new genera (phi KZ and EL). Restriction enzyme analysis revealed the mosaic genome structure in four phages of the phi KZ species (phi KZ, Lin21, NN, and PTB80) and two phages of the EL species (EL and RU). Comparisons with respect to phage particle size, number of structural proteins, and the N-terminal se...