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At least 19 recordsLinked to original sources
PubMed1983

Biochemical relationship among three F-type pyocins, pyocin F1, F2, and F3, and phage KF1.

The immunological and the biochemical relationships between F-type pyocins and phage KF1, which is cross-reactive with anti-F-type pyocin sera, were studied. The primary structures of six subunit proteins of each pyocin were also compared among three F-type pyocins, pyocin F1, F2, and F3. Both anti-pyocin F1 and anti-pyocin F3 sera gave precipitin bands with phage KF1 by Ouchterlony's test, and were found to bind to minor subunit proteins P3 and P6 of the phage, which were separated by SDS-polyacrylamide gel electrophoresis. Electron microscopic studies showed that these sera bound to some loci of the rod part of the phage tail. These results showed that the subunit proteins P3 and P6 carried antigenically common parts to F-type pyocin and that P3 and/or P6 were components of the rod part of the phage KF1. The subunit proteins P3 and P6 of the phage were of the same mobilities in SDS-polyacrylamide gel electrophoresis as those of band 1 and band 5 of F-type pyocins, respectively. Tryptic peptide mapping after iodination with 125I also showed a partial homology between P3 and band 1, and between P6 and band 5. The tryptic peptide mapping of the six subunit proteins of each F-type pyocin showed that the primary structure of subunit protein band 1 was almost the same among these pyocins, and subunit protein bands 2, 3, 5, and 6 showed were similar. Only subunit protein band 4 was different among these pyocins. The difference in the action spectra of pyocin F1, F2, and F3 is probably due to the difference in the primary structure of subunit protein band 4, which is a component of the fiber part.

Autoradiography↗
PubMed1981

Purification and properties of an S-type pyocin, pyocin AP41.

Pyocin AP41, a protease-sensitive bacteriocin produced by Pseudomonas aeruginosa PAF41, was purified to a homogeneous state and characterized. The molecular weight of this pyocin was about 95,000 as determined by the combination of gel filtration and sedimentation velocity analysis. This pyocin was a complex of two kinds of polypeptides. Highly purified preparations showed two protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their apparent molecular weights were 90,000 and 6,000 to 7,000, respectively. Two proteins could be separated by gel filtration in the presence of 6 M urea. Amino acid compositions of these components were determined. The large component had pyocin activity similar to the complex, whereas the small component did not. Sensitive cells were killed by this pyocin only under growing conditions and with single-hit kinetics. The pyocin-treated cells lysed in about 30 min with concomitant production of their resident pyocins or phages. The induced production of resident pyocins caused by pyocin AP41 depended on a recA gene function.

Amino Acids↗
PubMed1995

Molecular characterization of pyocin S3, a novel S-type pyocin from Pseudomonas aeruginosa.

The genetic determinant for the soluble pyocin S3 was isolated from a genomic library constructed in the plasmid pGV1122, of Pseudomonas aeruginosa strain P12 isolated from a cystic fibrosis patient. The nucleotide sequence of a 3270-base pair DNA fragment was determined, and the two structural genes, pyoS3A and pyoS3I, and the 3'- and 5'-flanking regions were localized. Transcription (Northern blot) analysis showed that the two genes were co-transcribed. The genes pyoS3A and pyoS3I code for polypeptides of 767 and 154 amino acids, respectively, with calculated molecular weights of 81,385 and 17,047. Pyocin S3 was produced in Escherichia coli from a plasmid and purified as a complex of two components (S3A and S3I) corresponding to the pyoS3A and pyoS3I gene products, respectively. The S3A component, like pyocin S3, had a killing effect involving DNase activity and was inhibited by the S3I protein. Comparisons of the predicted amino acid sequence of the two components of pyocin S3 to those of pyocins S1, S2, and AP41 indicate that pyocin S3 is a new type of S-type pyocin.

Amino Acid Sequence↗
PubMed1983

Genetic determinant of pyocin R2 in Pseudomonas aeruginosa PAO. II. Physical characterization of pyocin R2 genes using R-prime plasmids constructed from R68.45.

The chromosome segment which contains the genes responsible for production of pyocin R2 in P. aeruginosa PAO was defined physically using R-prime plasmids constructed in vivo from R68.45. The previous conclusion from genetic mapping that the cluster of pyocin R2 genes is located in between trpC and trpE genes was confirmed by deletion mapping of various R prime plasmids bearing the trpC gene. The pyocin R2 gene cluster was further localized on two contiguous HindIII fragments of 16 kb and 8.0 kb. PML14 strain, in which R-type pyocin genes were completely deleted, had only one 11 kb HindIII fragment instead. Heteroduplexes between this 11 kb fragment with the two HindIII fragments of PAO revealed that the cluster of pyocin R2 genes was an insertion 13 kb long.

Bacteriocins↗
PubMed1975

Pyocin-sensitivity testing as a method of typing Pseudomonas aeruginosa: use of "phage-free" preparations of pyocin.

A method for pyocin-sensitivity typing by means of "phage-free" preparations of pyocin is described. The method was tested on 227 isolates of P. aeruginosa, collected from 34 different foci of infection in hospitals in the British Isles and the results were compared with those for combined serological and phage typing of all strains and pyocin production of 105 of the isolates. It is concluded that pyocin-sensitivity typing is a simple and reliable method giving a high degree of discrimination, comparable to that of combined serological and phage typing, and it is suitable for use in routine hospital laboratories.

Bacteriocins↗
PubMed1983

Genetic determinant of pyocin R2 in Pseudomonas aeruginosa PAO. I. Localization of the pyocin R2 gene cluster between the trpCD and trpE genes.

Thirty-seven mutants defective in pyocin R2 production in the P. aeruginosa PAO strain were subjected to fine mapping of pyocin R2 genes by transduction with phage F116L. Sixteen complementation groups (designated prtA through prtP) involved in pyocin R2 production were tentatively identified by complementation tests using phage F116L. Their linkages to trpC and trpE markers and fine mapping by three point crosses demonstrated that most of the mutations (prtA through prtN) were located in between trpC and trpE, and that the prtP mutation was localized outside this major prt cluster but in the proximity of the rifA and strA region.

Bacteriocins↗
PubMedDate not supplied

Possibility of using purified pyocins for typing Pseudomonas aeruginosa: purification of pyocins and sensitivity of P. aeruginosa in different tests.

Two types of pyocins were simultaneously found in Pseudomonas aeruginosa strains HCP2. According to their structures, they belonged to the types classified as R and F, respectively, and were named HCP2-R and HCP2-F. The sensitivity of 87 strains of P. aeruginosa of clinical origin to pyocins of strain HCP2 was compared in different types of tests. Results indicated that the use of the purified pyocins for the typing of P. aeruginosa provides data which are easier to control and interpret.

Bacteriocins↗
PubMed1981

Interaction with lectins and differential wheat germ agglutinin binding of pyocin 103-sensitive and -resistant Neisseria gonorrhoeae.

Strains of Neisseria gonorrhoeae were treated with pyocin 611 131 (pyocin 103) from Pseudomonas aeruginosa PA103, and isogenic resistant variants were isolated. The interaction of pyocin-sensitive and isogenic pyocin-resistant strains with wheat germ agglutinin (WGA) agglutinated all pyocin-sensitive, but not pyocin-resistant, strains. Binding of WGA to three pyocin-sensitive strains and their isogenic pyocin-resistant variants was examined quantitatively by using fluorescein-conjugated lectin. Pyocin-resistant strains maximally bound one-third to one-eighth the quantity of WGA bound by isogenic-sensitive strains. Linear Scatchard plots revealed homogeneous WGA-binding sites on three pyocin-sensitive and one pyocin-resistant strains. Biphasic Scatchard plots, obtained with two pyocin-resistant strains, show that WGA-binding sites in these strains are heterogeneous. The number of WGA-binding sites for pyocin-sensitive organisms ranged from 8 x 10(5) to 1 x 10(6) sites per coccus and from 1 x 10(5) to 3 x 10(5) sites per coccus for pyocin-resistant strains. The apparent association constant for WGA binding to pyocin-sensitive strains ranged from 3 x 10(6) to 6 x 10(6) liters/mol and from 6 x 10(6) to 1 x 10(7) liters/mol for pyocin-resistant strains. Gonococcal lipopolysaccharide was shown to serve as the pyocin 103 receptor by inhibition of pyocin activity. Lipopolysaccharide from a pyocin 103-resistant strain was not able to inhibit pyocin 103 activity. Pyocin 103 resistance was correlated with a structural alteration involving N-acetylglucosamine residues in gonococcal lipopolysaccharide. Based on interactions with wheat germ, soybean, and ricin lectins, a model of lipopolysaccharide structure in N. gonorrhoeae is presented.

Agglutination↗