| isolation and characterization of mutants of the plasmid pkm101 deficient in their ability to enhance mutagenesis and repair. | a screening procedure was developed for identifying mutants of the plasmid pkm101 no longer capable of enhancing mutagenesis. the test was based on the large pkm101-mediated increase in the number of gal+ papillae observed on colonies of salmonella typhimurium gal mutants plated on tetrazolium-galactose plates in the presence of a mutagen. the pkm101 mutant plasmids transferred normally, were stably maintained in cells, caused normal levels of ampicillin resistance, and still imparted sensitivit ... | 1978 | 346562 |
| plasmids of incompatibility group p code for the capacity to propagate bacteriophage ike. | seven of eight plasmids of incompatibility group p were found to code for the capacity to propagate bacteriophage ike in escherichia coli. six of the seven plasmids allowed propagation of ike by one bacterial host (rg172) but not by another (rg176); the other plasmid allowed ike propagation by both hosts. ike propagation by a number of e. coli k-12 strains was quite variable. ikeh, an extended host range mutant of ike, was found to plaque specifically on n+ and p+ strains. | 1978 | 361724 |
| single-cell studies on the carrier state of bacteriophage ike, a virus specific for conjugative plasmids of the n incompatibility and conjugative group. | | 1978 | 371770 |
| variant forms of matrix protein in escherichia coli b/r bearing n plasmids. | plasmids of the n incompatibility group have been found to decrease or virtually eliminate the synthesis of the 36,500 dalton outer membrane matrix protein of their escherichia coli b/r hosts (iyer, r. (1977) biochim. biophys. acta 470, 258--272 and iyer, r., darby, v. and holland, i.b. (1978) febs lett. 85, 127--132) or modify its composition. although the 34,000 dalton tol g protein is slightly increased in some strains, it is identical in composition to the homologous protein from the plasmid ... | 1979 | 383151 |
| genetic properties of rm 98, an r plasmid of salmonella which determines sensitivity to the phage ike. | an r plasmid of salmonella, rm98, which determines sensitivity ot the phage ike (ikes) and confers resistance to ampicillin (ap), streptomycin (sm) and tetracycline (tc) was studied for its genetic properties in salmonella typhimurium and escherichia coli, transduction of rm98 by p22 in salmonella yielded transductants of which some had acquired all the recognizable markers (ap, sm, tc, ikes and resistance transfer factor or rtf) associated with rm98. this transduction pattern resembles the p22 ... | 1976 | 779352 |
| changes in membrane proteins of escherichia coli k12 mediated by bacteriophage ike-specific plasmids. | at least 3 minor proteins have been detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis in the unseparated (31 000 daltons) and inner membranes (53 000 and 86 000 daltons) of a non-piliated strain of e. coli k12 bearing the phage ike-specific resistance plasmid rm98 (tra+); these proteins are lacking in its tra- derivative and in the plasmidless host. in contrast, in another k12 host carrying each of different ike-specific colicinogenic factors, an extra 30 000 dalton protein i ... | 1976 | 793620 |
| unusual characteristics of the receptor for the n sex factor-specific filamentous phage ike. | | 1975 | 1102391 |
| nucleotide sequence of the genome of the filamentous bacteriophage i2-2: module evolution of the filamentous phage genome. | the nucleotide sequence of the circular single-stranded genome of the filamentous escherichia coli phage i2-2 has been determined and compared with those of the filamentous e. coli phages ff(m13, fl, or fd) and ike. the i2-2 dna sequence comprises 6744 nucleotides; 139 nucleotides less than that of the n- and i2-plasmid-specific phage ike, and 337 (336) nucleotides more than that of the f-plasmid-specific phage ff. nucleotide sequence comparisons have indicated that i2-2, ike, and ff have a simi ... | 1992 | 1556749 |
| the adsorption protein of phage ike. localization by deletion mutagenesis of domains involved in infectivity. | we constructed a set of plasmid-encoded internal deletion mutants within the gene for the adsorption protein (g3p) of phage ike. all mutant proteins still contain the signal and membrane anchor sequence, as those are known to be indispensable for proper localization and hence assembly of the g3p into phage. these various deletions comprise all internal parts of the protein and are properly incorporated into phage, which remarkably shows that signal and anchor sequence are sufficient for incorpor ... | 1992 | 1560775 |
| gene v protein-mediated translational regulation of the synthesis of gene ii protein of the filamentous bacteriophage m13: a dispensable function of the filamentous-phage genome. | introduction of a deletion in the genome of wild-type m13 bacteriophage that eliminates translational repression of m13 gene ii by its cognate gene v protein had no effect on phage viability. furthermore, it was noted that gene v protein of phage ike, a distant relative of m13, does not function as a translational repressor of its cognate gene ii protein. the data strongly indicate that the gene v protein-mediated control of gene ii expression in bacteriophage m13 is an evolutionary relic of the ... | 1992 | 1729248 |
| assignment of the 1h nmr spectrum and secondary structure elucidation of the single-stranded dna binding protein encoded by the filamentous bacteriophage ike. | by means of 2d nmr techniques, all backbone resonances in the 1h nmr spectrum of the single-stranded dna binding protein encoded by gene v of the filamentous phage ike have been assigned sequence specifically (at ph 4.6, t = 298 k). in addition, a major part of the side chain resonances could be assigned as well. analysis of noesy data permitted the elucidation of the secondary structure of ike gene v protein. the major part of this secondary structure is present as an antiparallel beta-sheet, i ... | 1992 | 1734970 |
| genetic analysis of the transfer region of the incn plasmid n3. | using lambda::tn5 insertion mutagenesis and screening for conjugation, the boundaries of the incn plasmid n3 transfer region were determined. sensitivity to phage ike infection was used to monitor that part of the n3 transfer region which harbours genes for pilus synthesis and assembly. we cloned this region, creating plasmid pbg21. escherichia coli cells transformed with pbg21 became sensitive to phage ike and produced pili, as shown by electron microscopy. various plasmid constructions contain ... | 1990 | 1980957 |
| structure of the dna binding wing of the gene-v encoded single- stranded dna binding protein of the filamentous bacteriophage m13. | the structure in solution of a beta-loop in mutant y41h of the single-stranded dna binding protein encoded by gene-v of the filamentous phage m13 has been elucidated using 2-dimensional 1h-nuclear magnetic resonance techniques. furthermore, these studies enabled us to demonstrate that an identical structural element is present in wild-type gene-v-protein and that this element intimately is involved in the binding of gene-v-protein to single-stranded dna. it is shown that the structure of the dna ... | 1990 | 2307226 |
| two-dimensional 1h nuclear magnetic resonance studies on the gene v-encoded single-stranded dna-binding protein of the filamentous bacteriophage ike. i. structure elucidation of the dna-binding wing. | two-dimensional nuclear magnetic resonance techniques were used to obtain residue- and sequence-specific assignments in the 1h spectrum of the single-stranded dna-binding protein encoded by gene v of the filamentous phage ike (ike gvp). the residue-specific assignments are based on the analysis of j-correlated spectra, i.e. correlated spectroscopy and homonuclear-hartmann-hahn total correlated spectroscopy. complete assignments of side-chain spin systems, e.g. long side-chains, were, to a major ... | 1989 | 2704037 |
| two-dimensional 1h nuclear magnetic resonance studies on the gene v-encoded single-stranded dna-binding protein of the filamentous bacteriophage ike. ii. characterization of the dna-binding wing with the aid of spin-labelled oligonucleotides. | the dna-binding domain of the single-stranded dna-binding protein ike gvp was studied by means of 1h nuclear magnetic resonance, through use of oligonucleotides of two and three adenyl residues in length, that were spin-labelled at their 3' and/or 5' termini. these spin-labelled ligands were found to cause line broadening of specific protein resonances when bound to the protein, although they were present in small quantities, i.e. of the order of 0.04 molar equivalent and less. the line broadeni ... | 1989 | 2704038 |
| fii, a bacterial locus required for filamentous phage infection and its relation to colicin-tolerant tola and tolb. | we describe mutations in a new bacterial locus, designated fii, which do not allow the filamentous bacteriophage f1 to infect bacteria harboring the f plasmid. mutations at this locus do not affect the ability of f plasmid-containing bacteria to undergo conjugation or be infected by the f plasmid-specific rna phage f2. the filamentous phage can still adsorb to the f sex pilus, but the dna is unable to enter the bacteria. all fii mutants become tolerant to colicins e1, e2, and e3. strains with am ... | 1986 | 3001021 |
| plasmid pkun9, a versatile vector for the selective packaging of both dna strands into single-stranded dna-containing phage-like particles. | a versatile vector plasmid, pkun9, has been constructed which, simply by infecting cells harboring this plasmid with either bacteriophage ike or ff (m13, fd, and fl), permits the selective packaging of both of its dna strands into, single-stranded (ss) dna-containing, phage-like particles. the plasmid, which is a derivative of plasmid puc9 [vieira and messing, gene 19 (1982) 269-276], contains in opposite orientations the replication origins and contiguous packaging signals of the distantly rela ... | 1986 | 3009274 |
| functional analysis of the adsorption protein of two filamentous phages with different host specificities. | the gene 3 coding for one minor coat protein (adsorption protein) of phage ike was cloned into an expression plasmid and overproduced. the presence of a promoter for this gene could be demonstrated as well as the incorporation of the ike gene 3 protein (g3p) into the cytoplasmic membrane of host cells. when 110 carboxy-terminal amino acids were deleted, the truncated protein was translocated across the cytoplasmic membrane into the periplasm. thus the deleted amino acids bear a membrane anchor d ... | 1988 | 3171545 |
| a preliminary structure for the dna binding protein from bacteriophage ike. | a modelling procedure has been utilized to obtain a preliminary three-dimensional structural model for the bacteriophage ike dna binding protein (ike-dbp) based on the known high resolution x-ray diffraction structure of a functionally related protein (g5bp) from bacteriophage fd. the degree of structural homology observed is much higher than the 44% primary sequence identity between these proteins would indicate. these studies suggest ike-dbp, like g5bp, is composed of a central three-stranded ... | 1987 | 3270530 |
| sequence comparison of single-stranded dna binding proteins and its structural implications. | the primary sequences were compared among several proteins: gene product 5 protein (gp5) from phage m13; pike from phage ike; gene product 32 protein (gp32) from phage t4; reca, ssb and ssf from escherichia coli. these proteins bind strongly and cooperatively to single-stranded dna with no sequence specificity. gp5 is the smallest in this group and its three-dimensional structure is well-characterized. using the entire sequence of gp5 as a template we searched for the regions in other single-str ... | 1987 | 3295261 |
| 1h-nmr studies on the gene-5-encoded single-stranded dna binding protein of the filamentous bacteriophage ike. general spectral and structural features. | under physiological conditions and at concentrations needed for nmr studies, severe aggregation of the gene-5 protein of the filamentous phage ike occurs. conditions are described for which well-resolved 1h-nmr spectra of the protein can be obtained. the aromatic part of the spectrum is analyzed by means of two-dimensional nmr techniques; a complete interpretation is presented. oligonucleotide binding studies reveal that just one phenylalanyl residue and one tyrosyl residue are influenced by the ... | 1987 | 3308460 |
| mike, a chimeric filamentous phage designed for the separate production of either dna strand of pkun vector plasmids by f+ cells. | to enable the separate production of either dna strand of recombinant pkun plasmids [peeters et al., gene 41 (1986) 39-46] by conjugation-deficient f+ cells a chimeric ff/ike filamentous phage, mike, has been constructed. its genome contains the functions required for asymmetric dna replication from the n-plasmid specific filamentous phage ike, and the functions required for host cell penetration, single-stranded dna accumulation, phage assembly, and secretion from the f-plasmid specific filamen ... | 1986 | 3542722 |
| comparison of the dna sequences involved in replication and packaging of the filamentous phages ike and ff (m13, fd, and f1). | the product of gene ii of the distantly related, filamentous, single-stranded dna phages ike and ff (m13, fd, and f1) is the only phage-encoded protein that is required for the replication of their double-stranded replicative form dna. with the aid of recombinant plasmids containing the origins of viral strand replication [(+)-origins] of both ike and ff, we demonstrated that initiation but not termination of viral strand replication by gene ii protein is restricted to its cognate (+)-origin. if ... | 1987 | 3556112 |
| nucleotide sequence and genetic organization of the genome of the n-specific filamentous bacteriophage ike. comparison with the genome of the f-specific filamentous phages m13, fd and f1. | the nucleotide sequence and genetic organization of the genome of the n-specific filamentous single-stranded dna phage ike has been established and compared with that of the f-specific filamentous phages m13, fd and f1 (ff). the ike dna sequence comprises 6883 nucleotides, which is 476 (475) nucleotides more than the nucleotide sequence of the ff genome. the data indicate that ike and ff have evolved from a common ancestor (overall homology approx. 55%) and that their genomes contain ten homolog ... | 1985 | 3981635 |
| absence of a pilus receptor for filamentous phage ike. | | 1974 | 4600625 |
| inci2 plasmids specify sensitivity to filamentous bacteriophage ike. | bacterial strains carrying the derepressed incompatibility group inci2 plasmids tp114drp-l or r721pilc were lysed by the filamentous bacteriophages ike, i2-2, and x. phage i2-2 was serologically related to ike, but phage x was not. phage ike adsorbed to the tips of thick pili determined by the inci2 plasmids, but not to the well-known thin i2 pili. | 1983 | 6131882 |
| characterization of the dna binding protein encoded by the n-specific filamentous escherichia coli phage ike. binding properties of the protein and nucleotide sequence of the gene. | a dna binding protein encoded by the filamentous single-stranded dna phage ike has been isolated from ike-infected escherichia coli cells. fluorescence and in vitro binding studies have shown that the protein binds co-operatively and with a high specificity to single-stranded but not to double-stranded dna. from titration of the protein to poly(da) it has been calculated that approximately four bases of the dna are covered by one monomer of protein. these binding characteristics closely resemble ... | 1983 | 6312049 |
| accessibility and dynamics of cys residues in bacteriophage ike and m13 major coat protein mutants. | the filamentous bacteriophage major coat protein occurs as a membrane-spanning assembly intermediate prior to incorporation into the lipid-free virion. to gain insight into how this small, multifunctional protein is able to be stably incorporated into both of these distinct environments, the reactive sulfhydryl group of ike and m13 coat protein cys mutants was exploited to probe the mobility and environment of this residue at several loci within the hydrophobic domain of these proteins. ike muta ... | 1995 | 7547983 |
| mutagenesis of bacteriophage ike major coat protein transmembrane domain: role of an interfacial proline residue. | the transmembrane (tm) domain of the 53-residue major coat protein of the m13-related bacteriophage ike (residues 24-42: lisqtwpvvttvvvagvli) has been subjected to randomized mutagenesis to probe the conformation and stability of the tm domain, as well as the effect of structurally-important residues such as proline. tm mutants were obtained by the eckstein method of site-directed mutagenesis using the ike genome as template so as to eliminate the need for subcloning. over 40 single- and double- ... | 1993 | 8216279 |
| exploration of the single-stranded dna-binding domains of the gene v proteins encoded by the filamentous bacteriophages ike and m13 by means of spin-labeled oligonucleotide and lanthanide-chelate complexes. | scrutiny of noe data available for the protein encoded by gene v of the filamentous phage ike (ike gvp), resulted in the elucidation of a beta-sheet structure which is partly five stranded. the dna-binding domain of ike gvp was investigated using a spin-labeled deoxytrinucleotide. the paramagnetic-relaxation effects observed in the 1h-nmr spectrum of ike gvp, upon binding of this dna fragment, could be visualized using two-dimensional difference spectroscopy. in this way, the residues present in ... | 1993 | 8375389 |
| interchangeability of the adsorption proteins of bacteriophages ff and ike. | the wild-type adsorption protein (g3p) of filamentous phage ike cannot be exchanged with its analogous protein in the related ff (m13, fd, and f1) phage particles. deletion mutants of the protein, however, are assembled into ff phage particles. these hybrid ff phage particles bearing deleted ike g3p attach to n pili, thus conserving the host attachment property of the protein but not its infection-initiating function. this means that the attachment specificity is determined by ike g3p independen ... | 1993 | 8497054 |
| structure and dynamics of bacteriophage ike major coat protein in mpg micelles by solution nmr. | the structure and dynamics of the 53-residue filamentous bacteriophage ike major coat protein in fully protonated myristoyllysophosphatidylglycerol (mpg) micelles were characterized using multinuclear solution nmr spectroscopy. detergent-solubilized coat protein [sequence: see text] mimics the membrane-bound "assembly intermediate" form of the coat protein which occurs during part of the phage life cycle. nmr studies of the ike coat protein show that the coat protein is largely alpha-helical, ex ... | 1996 | 8611498 |
| alpha-helical, but not beta-sheet, propensity of proline is determined by peptide environment. | proline is established as a potent breaker of both alpha-helical and beta-sheet structures in soluble (globular) proteins. thus, the frequent occurrence of the pro residue in the putative transmembrane helices of integral membrane proteins, particularly transport proteins, presents a structural dilemma. we propose that this phenomenon results from the fact that the structural propensity of a given amino acid may be altered to conform to changes imposed by molecular environment. to test this hypo ... | 1996 | 8692877 |
| biophysical characterization of wild-type and mutant bacteriophage ike major coat protein in the virion and in detergent micelles. | interactions between the filamentous bacteriophage major coat protein and its environment differ markedly between the membrane-bound assembly intermediate which spans the lipid bilayer and the phage coat protein which makes up the capsid of the virion. nonetheless, both reflect successful strategies to sequester the hydrophobic regions of the coat protein away from the aqueous milieu. to characterize the roles of individual residues in the conformation, stability, and oligomerization of the coat ... | 1996 | 8756704 |
| filamentous phage ike mrnas conserve form and function despite divergence in regulatory elements. | as a means of determining whether there has been selection to conserve the basic pattern of filamentous phage mrnas, the major mrnas representing genes ii to viii have been defined for a phage distantly related to the ff group specific for escherichia coli hosts bearing f pili. phage ike has a genome with 55% identity with the ff genome and infects e. coli strains bearing n pili. the results reveal a remarkably similar pattern of overlapping polycistronic mrnas with a common 3' end and unique 5' ... | 1997 | 9054970 |
| module swaps between related translocator proteins piv(f1), piv(ike) and puld: identification of a specificity domain. | in gram-negative bacteria, type ii and type iii secretion and filamentous phage assembly systems use related outer membrane proteins for substrate-specific transport across the outer membrane. we show here that the specificity domain of the phage f1 outer membrane protein piv is contained within the 149 n-terminal amino acid residues. when the piv(f1) specificity domain is fused to the translocator domain of the related piv of phage ike, the chimeric construct supports f1 but not ike assembly. f ... | 1997 | 9086275 |
| translation limits synthesis of an assembly-initiating coat protein of filamentous phage ike. | translation is shown to be downregulated sharply between genes v and vii of ike, a filamentous bacteriophage classed with the ff group (phages f1, m13, and fd) but having only 55% dna sequence identity to it. genes v and vii encode the following proteins which are used in very different amounts: pv, used to coat the large number of viral dna molecules prior to assembly, and pvii, used to serve as a cap with pix in 3 to 5 copies on the end of the phage particle that emerges first from escherichia ... | 1998 | 9457845 |
| translation at higher than an optimal level interferes with coupling at an intercistronic junction. | in pairs of adjacent genes co-transcribed on bacterial polycistronic mrnas, translation of the first coding region frequently functions as a positive factor to couple translation to the distal coding region. coupling efficiencies vary over a wide range, but synthesis of both gene products at similar levels is common. we report the results of characterizing an unusual gene pair, in which only about 1% of the translational activity from the upstream gene is transmitted to the distal gene. the inef ... | 2001 | 11722745 |