We have determined the precise point of transcrip tion initiation for five nif (nitrogen fixation... more We have determined the precise point of transcrip tion initiation for five nif (nitrogen fixation) operons of Klebsiella pneumoniae and sequenced the promoters. Our results show that nifF is transcribed in the opposite direction to that previously proposed for nif genes, that nifM is transcribed from two promoters, and that there is a promoter preceding MU but not nifx, and we present a revised map of nif transcripts. The nif promoters have a characteristic structure of 26 bp located between positions-1 and-26 upstream of the site of transcription initiation: CTGG..6bp...TTGCA...gbp...Py(+l). This structure, which has two regions of conserved sequence, shows no homology to the "consensus promoter" of enteric bacteria. Our results suggest that the-10 homology is equivalent to a "Pribnow box" for promoters expressed under nitrogen-starved conditions and that the-23 homology confers activator specificity on the nif promoters.
Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and ... more Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and halophilic archaea. They are permeable to ambient gases by diffusion and provide buoyancy, enabling cells to move upwards in liquid to access oxygen and/or light. In halobacteria, gas vesicle production is encoded in a 9-kb cluster of 14 genes (4 of known function). In cyanobacteria, the number of genes involved has not been determined. We now report the cloning and sequence analysis of an 8,142-bp cluster of 15 putative gas vesicle genes (gvp) from Bacillus megaterium VT1660 and their functional expression in Escherichia coli. Evidence includes homologies by sequence analysis to known gas vesicle genes, the buoyancy phenotype of E. coli strains that carry this gvp gene cluster, the presence of pressure-sensitive, refractile bodies in phase-contrast microscopy, structural details in phase-constrast microscopy, structural details in direct interference-contrast microscopy, and shape and size revealed by transmission electron microscopy. In B. megaterium, the gvp region carries a cluster of 15 putative genes arranged in one orientation; they are open reading frame 1 and gvpA
The nifF gene of Klebsiella pneumoniae was cloned into a multicopy plasmid in order to construct ... more The nifF gene of Klebsiella pneumoniae was cloned into a multicopy plasmid in order to construct a strain that synthesizes and retains an elevated concentration of the gene product relative to the wild-type strain. Characterization of the isolated flavodoxin, which serves as an electron donor to nitrogenase, shows unambiguously that it is the product of the nifF gene.
Biochemical and Biophysical Research Communications, May 1, 1970
Abstract Native DNA from a multiple drug resistant strain of Staphylococcus aureus and sensitive ... more Abstract Native DNA from a multiple drug resistant strain of Staphylococcus aureus and sensitive variants derived from it was eluted from poly-L-lysine kieselguhr columns with a linear gradient of NaCl in phosphate buffer. The appearance of satellite peaks in the continuous elution profiles obtained was closely correlated with the presence of plasmid controlled characters in these strains.
Record number, AU8201280. Titles, Recent advances in the genetics and regulation of nitrogen fixa... more Record number, AU8201280. Titles, Recent advances in the genetics and regulation of nitrogen fixation. Personal Authors, Kennedy, C.,Cannon, F.,Cannon, M.,Dixon, R.,Hill, S.,Jensen, J.,SushilKumar,McLean, P.,Merrick, M.,Robson, R.,Postgate, J. (Sussex Univ., Brighton (UK) ...
Introduction: This discussion is intended to encompass the steps necessary to implement a compute... more Introduction: This discussion is intended to encompass the steps necessary to implement a computer based information system in the substation. The purpose of the system is to monitor substation apparatus for maintenance and planning purposes, and to integrate and present information gathered from various substation IEDs to local or remote utility entities. To implement a substation information system in a substation, several areas should be considered:
EXTENSINS (EXTs) are a 65-member subfamily of hydroxyproline-rich glycoproteins (HRGPs) of which ... more EXTENSINS (EXTs) are a 65-member subfamily of hydroxyproline-rich glycoproteins (HRGPs) of which 20 putatively form crosslinking networks in the cell wall. These 20 classical EXTs are involved at the start of new wall assembly as evidenced by a requirement for EXT3 during cytokinesis, and the ability of some EXTs to polymerize in vitro into dendritic patterns. EXT3 was previously shown to form pulcherosine (three Tyrosines) cross-links. Little direct data exists on the other 19 classical EXTs. Here, we describe the phenotypes of ext18 mutants and rescued progeny as well as associated expression profiles of all 20 classical EXT genes. We found that EXT18 is required for full male fertility, as well as for normal vegetative growth. EXT18 has potential to form crosslinking networks via di-iso-di-tyrosine (four Tyrosines) covalent bonds, and not via pulcherosine due to deficit of lone Tyrosines. This together with ext18 defective pollen grains and pollen tubes, and reduced plant size, s...
Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and ... more Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and halophilic archaea. They are permeable to ambient gases by diffusion and provide buoyancy, enabling cells to move upwards in liquid to access oxygen and/or light. In halobacteria, gas vesicle production is encoded in a 9-kb cluster of 14 genes (4 of known function). In cyanobacteria, the number of genes involved has not been determined. We now report the cloning and sequence analysis of an 8,142-bp cluster of 15 putative gas vesicle genes (gvp) from Bacillus megaterium VT1660 and their functional expression in Escherichia coli. Evidence includes homologies by sequence analysis to known gas vesicle genes, the buoyancy phenotype of E. coli strains that carry this gvp gene cluster, the presence of pressure-sensitive, refractile bodies in phase-contrast microscopy, structural details in phase-contrast microscopy, structural details in direct interference-contrast microscopy, and shape and si...
Polyhydroxyalkanoic acids (PHA) are carbon and energy storage polymers that accumulate in inclusi... more Polyhydroxyalkanoic acids (PHA) are carbon and energy storage polymers that accumulate in inclusion bodies in many bacteria and archaea in response to environmental conditions. This work presents the results of a study of PHA inclusion body-associated proteins and an analysis of their coding region in Bacillus megaterium 11561. A 7, 917-bp fragment of DNA was cloned and shown to carry a 4,104-bp cluster of 5 pha genes, phaP, -Q, -R, -B, and -C. The phaP and -Q genes were shown to be transcribed in one orientation, each from a separate promoter, while immediately upstream, phaR, -B, and -C were divergently transcribed as a tricistronic operon. Transfer of this gene cluster to Escherichia coli and to a PhaC- mutant of Pseudomonas putida gave a Pha+ phenotype in both strains. Translational fusions to the green fluorescent protein localized PhaP and PhaC to the PHA inclusion bodies in living cells. The data presented are consistent with the hypothesis that the extremely hydrophilic prot...
Although a large number of embryo mutants have been studied, mostly at the morphological level, t... more Although a large number of embryo mutants have been studied, mostly at the morphological level, the critical molecular and cellular events responsible for embryogenesis are unknown. Here, we report that using an enhancer-trap embryo mutant of Arabidopsis, we identified a gene, ROOT-SHOOT-HYPOCOTYL-DEFECTIVE (RSH), that is essential for the correct positioning of the cell plate during cytokinesis in cells of the developing embryo. We traced the earliest point of influence of RSH to the first asymmetrical division of the zygote. Homozygous rsh embryos were defective morphologically, had irregular cell shape and size, and germinated to form agravitropic-defective seedlings incapable of further development. The RSH gene encodes a Hyp-rich glycoprotein-type cell wall protein. RSH localized to the cell wall throughout the embryo and to a few well-defined postembryonic sites. Although several lines of evidence from previous work suggest that the cell wall is involved in development, the pr...
Although a large number of embryo mutants have been studied, mostly at the morphological level, t... more Although a large number of embryo mutants have been studied, mostly at the morphological level, the critical molecular and cellular events responsible for embryogenesis are unknown. Here, we report that using an enhancer-trap embryo mutant of Arabidopsis, we identified a gene, ROOT-SHOOT-HYPOCOTYL-DEFECTIVE ( RSH ), that is essential for the correct positioning of the cell plate during cytokinesis in cells of the developing embryo. We traced the earliest point of influence of RSH to the first asymmetrical division of the zygote. Homozygous rsh embryos were defective morphologically, had irregular cell shape and size, and germinated to form agravitropic-defective seedlings incapable of further development. The RSH gene encodes a Hyp-rich glycoprotein-type cell wall protein. RSH localized to the cell wall throughout the embryo and to a few well-defined postembryonic sites. Although several lines of evidence from previous work suggest that the cell wall is involved in development, the protein(s) involved remained elusive.
To review the number of microbiologically-confirmed cases of Johne's disease in f... more To review the number of microbiologically-confirmed cases of Johne's disease in farmed deer since 2000, and determine the prevalence of the bovine and ovine subtypes of Mycobacterium avium subsp paratuberculosis (M. paratuberculosis), using a highly specific polymerase chain reaction (PCR) test on samples from infected herds. The number of cases of M. paratuberculosis in farmed deer identified by culture or IS900 PCR was documented. A highly specific PCR test was applied to subtype M. paratuberculosis from BACTEC 12B cultures selected on the basis of one culture per deer herd, to give a wide coverage of herds in New Zealand. From January 2001 to October 2005, M. paratuberculosis was isolated from 1,141 farmed deer, and has now been identified by microbiological testing in over 600 deer herds in New Zealand. The bovine subtype of M. paratuberculosis was shown by a highly specific PCR test to be present in 91/95 herds examined; the ovine subtype was found in the remaining four herds. Since 2000, there has been a substantial increase in both the number of microbiologically-confirmed cases of Johne's disease in farmed deer and the number of infected herds. Johne's disease is now widespread and common in deer herds throughout New Zealand. Whilst the bovine subtype of M. paratuberculosis predominates in deer herds in New Zealand in which Johne's disease has been confirmed, the occasional finding of the ovine subtype highlights the need to consider both sheep and cattle as potential sources of infection for farmed deer.
Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and ... more Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and halophilic archaea. They are permeable to ambient gases by diffusion and provide buoyancy, enabling cells to move upwards in liquid to access oxygen and/or light. In halobacteria, gas vesicle production is encoded in a 9-kb cluster of 14 genes (4 of known function). In cyanobacteria, the number of genes involved has not been determined. We now report the cloning and sequence analysis of an 8,142-bp cluster of 15 putative gas vesicle genes (gvp) from Bacillus megaterium VT1660 and their functional expression in Escherichia coli. Evidence includes homologies by sequence analysis to known gas vesicle genes, the buoyancy phenotype of E. coli strains that carry this gvp gene cluster, the presence of pressure-sensitive, refractile bodies in phase-contrast microscopy, structural details in phase-constrast microscopy, structural details in direct interference-contrast microscopy, and shape and size revealed by transmission electron microscopy. In B. megaterium, the gvp region carries a cluster of 15 putative genes arranged in one orientation; they are open reading frame 1 and gvpA, -T, and -U, of which the last 11 genes, in a 5.7-kb gene cluster, are the maximum required for gas vesicle synthesis and function in E. coli. To our knowledge, this is the first example of a functional gas vesicle gene cluster in nonaquatic bacteria and the first example of the interspecies transfer of genes resulting in the synthesis of a functional organelle.
We have determined the precise point of transcrip tion initiation for five nif (nitrogen fixation... more We have determined the precise point of transcrip tion initiation for five nif (nitrogen fixation) operons of Klebsiella pneumoniae and sequenced the promoters. Our results show that nifF is transcribed in the opposite direction to that previously proposed for nif genes, that nifM is transcribed from two promoters, and that there is a promoter preceding MU but not nifx, and we present a revised map of nif transcripts. The nif promoters have a characteristic structure of 26 bp located between positions-1 and-26 upstream of the site of transcription initiation: CTGG..6bp...TTGCA...gbp...Py(+l). This structure, which has two regions of conserved sequence, shows no homology to the "consensus promoter" of enteric bacteria. Our results suggest that the-10 homology is equivalent to a "Pribnow box" for promoters expressed under nitrogen-starved conditions and that the-23 homology confers activator specificity on the nif promoters.
Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and ... more Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and halophilic archaea. They are permeable to ambient gases by diffusion and provide buoyancy, enabling cells to move upwards in liquid to access oxygen and/or light. In halobacteria, gas vesicle production is encoded in a 9-kb cluster of 14 genes (4 of known function). In cyanobacteria, the number of genes involved has not been determined. We now report the cloning and sequence analysis of an 8,142-bp cluster of 15 putative gas vesicle genes (gvp) from Bacillus megaterium VT1660 and their functional expression in Escherichia coli. Evidence includes homologies by sequence analysis to known gas vesicle genes, the buoyancy phenotype of E. coli strains that carry this gvp gene cluster, the presence of pressure-sensitive, refractile bodies in phase-contrast microscopy, structural details in phase-constrast microscopy, structural details in direct interference-contrast microscopy, and shape and size revealed by transmission electron microscopy. In B. megaterium, the gvp region carries a cluster of 15 putative genes arranged in one orientation; they are open reading frame 1 and gvpA
The nifF gene of Klebsiella pneumoniae was cloned into a multicopy plasmid in order to construct ... more The nifF gene of Klebsiella pneumoniae was cloned into a multicopy plasmid in order to construct a strain that synthesizes and retains an elevated concentration of the gene product relative to the wild-type strain. Characterization of the isolated flavodoxin, which serves as an electron donor to nitrogenase, shows unambiguously that it is the product of the nifF gene.
Biochemical and Biophysical Research Communications, May 1, 1970
Abstract Native DNA from a multiple drug resistant strain of Staphylococcus aureus and sensitive ... more Abstract Native DNA from a multiple drug resistant strain of Staphylococcus aureus and sensitive variants derived from it was eluted from poly-L-lysine kieselguhr columns with a linear gradient of NaCl in phosphate buffer. The appearance of satellite peaks in the continuous elution profiles obtained was closely correlated with the presence of plasmid controlled characters in these strains.
Record number, AU8201280. Titles, Recent advances in the genetics and regulation of nitrogen fixa... more Record number, AU8201280. Titles, Recent advances in the genetics and regulation of nitrogen fixation. Personal Authors, Kennedy, C.,Cannon, F.,Cannon, M.,Dixon, R.,Hill, S.,Jensen, J.,SushilKumar,McLean, P.,Merrick, M.,Robson, R.,Postgate, J. (Sussex Univ., Brighton (UK) ...
Introduction: This discussion is intended to encompass the steps necessary to implement a compute... more Introduction: This discussion is intended to encompass the steps necessary to implement a computer based information system in the substation. The purpose of the system is to monitor substation apparatus for maintenance and planning purposes, and to integrate and present information gathered from various substation IEDs to local or remote utility entities. To implement a substation information system in a substation, several areas should be considered:
EXTENSINS (EXTs) are a 65-member subfamily of hydroxyproline-rich glycoproteins (HRGPs) of which ... more EXTENSINS (EXTs) are a 65-member subfamily of hydroxyproline-rich glycoproteins (HRGPs) of which 20 putatively form crosslinking networks in the cell wall. These 20 classical EXTs are involved at the start of new wall assembly as evidenced by a requirement for EXT3 during cytokinesis, and the ability of some EXTs to polymerize in vitro into dendritic patterns. EXT3 was previously shown to form pulcherosine (three Tyrosines) cross-links. Little direct data exists on the other 19 classical EXTs. Here, we describe the phenotypes of ext18 mutants and rescued progeny as well as associated expression profiles of all 20 classical EXT genes. We found that EXT18 is required for full male fertility, as well as for normal vegetative growth. EXT18 has potential to form crosslinking networks via di-iso-di-tyrosine (four Tyrosines) covalent bonds, and not via pulcherosine due to deficit of lone Tyrosines. This together with ext18 defective pollen grains and pollen tubes, and reduced plant size, s...
Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and ... more Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and halophilic archaea. They are permeable to ambient gases by diffusion and provide buoyancy, enabling cells to move upwards in liquid to access oxygen and/or light. In halobacteria, gas vesicle production is encoded in a 9-kb cluster of 14 genes (4 of known function). In cyanobacteria, the number of genes involved has not been determined. We now report the cloning and sequence analysis of an 8,142-bp cluster of 15 putative gas vesicle genes (gvp) from Bacillus megaterium VT1660 and their functional expression in Escherichia coli. Evidence includes homologies by sequence analysis to known gas vesicle genes, the buoyancy phenotype of E. coli strains that carry this gvp gene cluster, the presence of pressure-sensitive, refractile bodies in phase-contrast microscopy, structural details in phase-contrast microscopy, structural details in direct interference-contrast microscopy, and shape and si...
Polyhydroxyalkanoic acids (PHA) are carbon and energy storage polymers that accumulate in inclusi... more Polyhydroxyalkanoic acids (PHA) are carbon and energy storage polymers that accumulate in inclusion bodies in many bacteria and archaea in response to environmental conditions. This work presents the results of a study of PHA inclusion body-associated proteins and an analysis of their coding region in Bacillus megaterium 11561. A 7, 917-bp fragment of DNA was cloned and shown to carry a 4,104-bp cluster of 5 pha genes, phaP, -Q, -R, -B, and -C. The phaP and -Q genes were shown to be transcribed in one orientation, each from a separate promoter, while immediately upstream, phaR, -B, and -C were divergently transcribed as a tricistronic operon. Transfer of this gene cluster to Escherichia coli and to a PhaC- mutant of Pseudomonas putida gave a Pha+ phenotype in both strains. Translational fusions to the green fluorescent protein localized PhaP and PhaC to the PHA inclusion bodies in living cells. The data presented are consistent with the hypothesis that the extremely hydrophilic prot...
Although a large number of embryo mutants have been studied, mostly at the morphological level, t... more Although a large number of embryo mutants have been studied, mostly at the morphological level, the critical molecular and cellular events responsible for embryogenesis are unknown. Here, we report that using an enhancer-trap embryo mutant of Arabidopsis, we identified a gene, ROOT-SHOOT-HYPOCOTYL-DEFECTIVE (RSH), that is essential for the correct positioning of the cell plate during cytokinesis in cells of the developing embryo. We traced the earliest point of influence of RSH to the first asymmetrical division of the zygote. Homozygous rsh embryos were defective morphologically, had irregular cell shape and size, and germinated to form agravitropic-defective seedlings incapable of further development. The RSH gene encodes a Hyp-rich glycoprotein-type cell wall protein. RSH localized to the cell wall throughout the embryo and to a few well-defined postembryonic sites. Although several lines of evidence from previous work suggest that the cell wall is involved in development, the pr...
Although a large number of embryo mutants have been studied, mostly at the morphological level, t... more Although a large number of embryo mutants have been studied, mostly at the morphological level, the critical molecular and cellular events responsible for embryogenesis are unknown. Here, we report that using an enhancer-trap embryo mutant of Arabidopsis, we identified a gene, ROOT-SHOOT-HYPOCOTYL-DEFECTIVE ( RSH ), that is essential for the correct positioning of the cell plate during cytokinesis in cells of the developing embryo. We traced the earliest point of influence of RSH to the first asymmetrical division of the zygote. Homozygous rsh embryos were defective morphologically, had irregular cell shape and size, and germinated to form agravitropic-defective seedlings incapable of further development. The RSH gene encodes a Hyp-rich glycoprotein-type cell wall protein. RSH localized to the cell wall throughout the embryo and to a few well-defined postembryonic sites. Although several lines of evidence from previous work suggest that the cell wall is involved in development, the protein(s) involved remained elusive.
To review the number of microbiologically-confirmed cases of Johne's disease in f... more To review the number of microbiologically-confirmed cases of Johne's disease in farmed deer since 2000, and determine the prevalence of the bovine and ovine subtypes of Mycobacterium avium subsp paratuberculosis (M. paratuberculosis), using a highly specific polymerase chain reaction (PCR) test on samples from infected herds. The number of cases of M. paratuberculosis in farmed deer identified by culture or IS900 PCR was documented. A highly specific PCR test was applied to subtype M. paratuberculosis from BACTEC 12B cultures selected on the basis of one culture per deer herd, to give a wide coverage of herds in New Zealand. From January 2001 to October 2005, M. paratuberculosis was isolated from 1,141 farmed deer, and has now been identified by microbiological testing in over 600 deer herds in New Zealand. The bovine subtype of M. paratuberculosis was shown by a highly specific PCR test to be present in 91/95 herds examined; the ovine subtype was found in the remaining four herds. Since 2000, there has been a substantial increase in both the number of microbiologically-confirmed cases of Johne's disease in farmed deer and the number of infected herds. Johne's disease is now widespread and common in deer herds throughout New Zealand. Whilst the bovine subtype of M. paratuberculosis predominates in deer herds in New Zealand in which Johne's disease has been confirmed, the occasional finding of the ovine subtype highlights the need to consider both sheep and cattle as potential sources of infection for farmed deer.
Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and ... more Gas vesicles are intracellular, protein-coated, and hollow organelles found in cyanobacteria and halophilic archaea. They are permeable to ambient gases by diffusion and provide buoyancy, enabling cells to move upwards in liquid to access oxygen and/or light. In halobacteria, gas vesicle production is encoded in a 9-kb cluster of 14 genes (4 of known function). In cyanobacteria, the number of genes involved has not been determined. We now report the cloning and sequence analysis of an 8,142-bp cluster of 15 putative gas vesicle genes (gvp) from Bacillus megaterium VT1660 and their functional expression in Escherichia coli. Evidence includes homologies by sequence analysis to known gas vesicle genes, the buoyancy phenotype of E. coli strains that carry this gvp gene cluster, the presence of pressure-sensitive, refractile bodies in phase-contrast microscopy, structural details in phase-constrast microscopy, structural details in direct interference-contrast microscopy, and shape and size revealed by transmission electron microscopy. In B. megaterium, the gvp region carries a cluster of 15 putative genes arranged in one orientation; they are open reading frame 1 and gvpA, -T, and -U, of which the last 11 genes, in a 5.7-kb gene cluster, are the maximum required for gas vesicle synthesis and function in E. coli. To our knowledge, this is the first example of a functional gas vesicle gene cluster in nonaquatic bacteria and the first example of the interspecies transfer of genes resulting in the synthesis of a functional organelle.
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Papers by Maura Cannon