A rod-shaped pseudomonas phage

Takeya, Kenji; Amako, Kazunobu

doi:10.1016/0042-6822(66)90317-5

Cited by 92 publications

(49 citation statements)

References 7 publications

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“…P. aeruginosa strains and construction of mutants. The P. aeruginosa mutants used in this study were derived from the wt strain PAK (52). Construction of the pilA null allele was previously described (18), as were constructs for the pilT and pilB mutations (50).…”

Section: Methodsmentioning

confidence: 99%

Genetic and Functional Analyses of PptA, a Phospho-Form Transferase Targeting Type IV Pili inNeisseria gonorrhoeae

Næssan

Egge-Jacobsen

Heiniger³

et al. 2008

J Bacteriol

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The PilE pilin subunit protein of Neisseria gonorrhoeae undergoes unique covalent modifications with phosphoethanolamine (PE) and phosphocholine (PC). The pilin phospho-form transferase A (PptA) protein, required for these modifications, shows sequence relatedness with and architectural similarities to lipopolysaccharide PE transferases. Here, we used regulated expression and mutagenesis as means to better define the relationships between PptA structure and function, as well as to probe the mechanisms by which other factors impact the system. We show here that pptA expression is coupled at the level of transcription to its distal gene, murF, in a division/cell wall gene operon and that PptA can act in a dose-dependent fashion in PilE phosphoform modification. Molecular modeling and site-directed mutagenesis provided the first direct evidence that PptA is a member of the alkaline phosphatase superfamily of metalloenzymes with similar metal-binding sites and conserved structural folds. Through phylogenetic analyses and sequence alignments, these conclusions were extended to include the lipopolysaccharide PE transferases, including members of the disparate Lpt6 subfamily, and the MdoB family of phosphoglycerol transferases. Each of these enzymes thus likely acts as a phospholipid head group transferase whose catalytic mechanism involves a trans-esterification step generating a protein-phospho-form ester intermediate. Coexpression of PptA with PilE in Pseudomonas aeruginosa resulted in high levels of PE modification but was not sufficient for PC modification. This and other findings show that PptA-associated PC modification is governed by as-yet-undefined ancillary factors unique to N. gonorrhoeae.

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Section: Methodsmentioning

confidence: 99%

Genetic and Functional Analyses of PptA, a Phospho-Form Transferase Targeting Type IV Pili inNeisseria gonorrhoeae

Næssan

Egge-Jacobsen

Heiniger³

et al. 2008

J Bacteriol

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“…field from the intensities of the 1 H and 13 C Fourier transformed nutation spectra, respectively (see Table S2 for the 1 …”

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confidence: 99%

Conformational dynamics of an intact virus: Order parameters for the coat protein of Pf1 bacteriophage

Lorieau

Day²,

McDermott

2008

Proc. Natl. Acad. Sci. U.S.A.

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This study has examined the atomic-level dynamics of the protein in the capsid of filamentous phage Pf1. This capsid consists of Ϸ7,300 small subunits of only 46 aa in a helical array around a highly extended, circular single-stranded DNA molecule of 7,349 nt. Measurements were made of site-specific, solid-state NMR order parameters, ͗S͘, the values which are dimensionless quantities between 0 (mobile) and 1 (static) that characterize the amplitudes of molecular bond angular motions that are faster than microseconds. It was found that the protein subunit backbone is very static, and of particular interest, it appears to be static at residues glycine 15 and glutamine 16 where it had been previously thought to be mobile. In contrast to the backbone, several side chains display large-amplitude angular motions. Side chains on the virion exterior that interact with solvent are highly mobile, but surprisingly, the side chains of residues arginine 44 and lysine 45 near the DNA deep in the interior of the virion are also highly mobile. The largeamplitude dynamic motion of these positively charged side chains in their interactions with the DNA were not previously expected. The results reveal a highly dynamic aspect of a DNA-protein interface within a virus.solid-state NMR ͉ motion ͉ side chain T he Pf1 bacteriophage is a 2-m-long filamentous virus that infects Pseudomonas aeruginosa strain K (1, 2). The virion consists of a circular single-stranded DNA genome of 7,349 nt (3) within a cylindrical capsid of Ϸ7,300 major coat protein subunits that have 1:1 stoichiometric interactions (4, 5) with nucleotides along the filament, as well as a small number of other proteins interacting with reverse turns of DNA at the ends. A variety of spectroscopic and diffraction studies of Pf1 have been carried out (5-19), including studies by solid-state NMR of the protein in the intact virion (16)(17)(18)(19), as in the present study, and by solution NMR of the isolated protein in detergent micelles (8,14) as a model of its structure in the membrane before virion assembly. Virion assembly occurs at the membrane in such a way that major coat protein subunits are packed in the filament as ␣-helices with their Nterminal regions on the outside and their C-terminal regions buried in the interior to interact with the DNA.One of the studies of the Pf1 virion by solid-state NMR was on magnetically aligned hydrated virions, and it characterized the path and orientation of the backbone of the ␣-helical major capsid protein subunit by means of 1 H-15 N polarization inversion spin exchange at the magic angle (PISEMA) (16,17). It was proposed that the subunit consists of an N terminus that forms a double hook, a C terminus with an unraveled ␣-helix, and a central portion of three ␣-helices with two bends near the center. An assumed capsid helical symmetry for the high-temperature form of the virion (6, 20) was used to generate the intersubunit contacts for a model of the capsid (16,17). In a more recent solid-state NMR study from our group (18, 19), m...

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“…(2) Phages specific for PSA pili: PP7 -an RNA phage (Bradley, 1966); Pf-a filamentous phage (Takeya & Amako, 1966); P04 (Bradley, 1973b); M6, C22, PE69, C5 (Bradley & Pitt, 1974), and F1 16 (Pemberton, 1973), with non-contractile tails.…”

Section: Bacteria and Bacteriophagesmentioning

confidence: 99%

An immunological study of the pili ofPseudomonas aeruginosa

Bradley

Pitt

1975

J. Hyg.

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SUMMARYAn attempt was made to correlate serological relationships determined by the pili, the flagella and the 0-somatic antigens of Pseudomonas aeruginosa, and to make a preliminary assessment of use of the pilus antigen as an epidemiological marker. A method is described for the preparation of antiserum specific for the 'normal' PSA pili of P. aeruginosa. A high titre of pilus antibodies was obtained by immunizing rabbits with mutants whose pill had lost their ability to retract into the cell. The 'normal' form of the organism, with retractile pili, was poorly agglutinated by high-titre anti-pilus serum, but suspensions of it that had been treated with osmium tetroxide showed greatly increased agglutinability. Antibody labelling for electron microscopy was used to determine the serological relations of pili and of flagella for P. aeruginosa strains belonging to different serological groups as defined by 0-somatic antigens. The distribution of pilar and flagellar antigens among strains was not correlated with the 0-somatic serotype. A strain of P. aeruginosa carrying a drug-resistance plasmid had fewer 'normal' PSA pili than the background strain.Pseudomonas aeruginosa normally possesses thin polar pill (fimbriae) which constitute one of the classes of heat-labile antigens of the organism. A previous study of the flagellar antigens (Pitt & Bradley, 1975), which are also heat-labile, was an essential preliminary to the development of a useful typing system based on heat-labile antigens. The present work extends this to the pilus antigens. The principle object is to define serological differences determined by pili, flagella, and heat-stable 0-somatic antigens. In order to make this comparison, it has been necessary to develop a method for preparing specific antisera against pili, free from flagellar and 0-somatic antibodies.Many studies have been made of P. aeruginosa pili; two basic types of pili have so far been established: (1) the 'normal' polar pili mentioned above (Bradley, 1966), to be called PSA pili for convenience and (2) the non-polar pili determined

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A rod-shaped pseudomonas phage

Cited by 92 publications

References 7 publications

Genetic and Functional Analyses of PptA, a Phospho-Form Transferase Targeting Type IV Pili inNeisseria gonorrhoeae

Genetic and Functional Analyses of PptA, a Phospho-Form Transferase Targeting Type IV Pili inNeisseria gonorrhoeae

Conformational dynamics of an intact virus: Order parameters for the coat protein of Pf1 bacteriophage

An immunological study of the pili ofPseudomonas aeruginosa

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