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By admin, on April 6th, 2012
Nat Struct Mol Biol . 2012 Apr 1; Selkrig J, Mosbahi K, Webb CT, Belousoff MJ, Perry AJ, Wells TJ, Morris F, Leyton DL, Totsika M, Phan MD, Celik N, Kelly M, Oates C, Hartland EL, Robins-Browne RM, Ramarathinam SH, Purcell AW, Schembri MA, Strugnell RA, Henderson IR, Walker D, Lithgow T Bacteria have mechanisms to export proteins for diverse purposes, including colonization of hosts and pathogenesis. A small number of archetypal bacterial secretion machines have been found in several groups of bacteria and mediate a fundamentally distinct secretion process
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Discovery of an archetypal protein transport system in bacterial outer membranes.
By admin, on March 31st, 2012
By admin, on March 30th, 2012
By admin, on March 29th, 2012
Acta Biol Hung . 2012 Mar; 63(1): 128-37 Elahwany AM Malolactate fermentation (MLF), which is known to decreases total acidity and improves the stability and quality of cider is conducted by Oenococcus oeni; the principal microorganism responsible for MLF under stress conditions. Understanding O.
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Genetic and physiological studies on Oenococcus oeni PsuI in response to ethanol stress.
By admin, on March 29th, 2012
Acta Biol Hung . 2012 Mar; 63(1): 128-37 Elahwany AM Malolactate fermentation (MLF), which is known to decreases total acidity and improves the stability and quality of cider is conducted by Oenococcus oeni; the principal microorganism responsible for MLF under stress conditions. Understanding O
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Genetic and physiological studies on Oenococcus oeni PsuI in response to ethanol stress.
By admin, on March 27th, 2012
ScientificWorldJournal . 2012; 2012: 402919 Maredia R, Devineni N, Lentz P, Dallo SF, Yu J, Guentzel N, Chambers J, Arulanandam B, Haskins WE, Weitao T Bacterial infections can be aggravated by antibiotic treatment that induces SOS response and vesiculation. This leads to a hypothesis concerning association of SOS with vesiculation
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Vesiculation from Pseudomonas aeruginosa under SOS.
By admin, on March 22nd, 2012
Int J Biochem Cell Biol . 2012 Mar 12; Aguilera L, Ferreira E, Giménez R, Fernández FJ, Taulés M, Aguilar J, Vega MC, Badia J, Baldomà L Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional housekeeping protein secreted by pathogens and involved in adhesion and/or virulence. Previously we reported that enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli secrete GAPDH into the culture medium
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Secretion of the housekeeping protein glyceraldehyde-3-phosphate dehydrogenase by the LEE-encoded type III secretion system in enteropathogenic Escherichia coli.
By admin, on March 22nd, 2012
Int J Biochem Cell Biol . 2012 Mar 12; Aguilera L, Ferreira E, Giménez R, Fernández FJ, Taulés M, Aguilar J, Vega MC, Badia J, Baldomà L Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional housekeeping protein secreted by pathogens and involved in adhesion and/or virulence. Previously we reported that enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli secrete GAPDH into the culture medium
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Secretion of the housekeeping protein glyceraldehyde-3-phosphate dehydrogenase by the LEE-encoded type III secretion system in enteropathogenic Escherichia coli.
By admin, on March 12th, 2012
Virology . 2012 Feb 29; Parent KN, Gilcrease EB, Casjens SR, Baker TS Coat proteins of tailed, dsDNA phages and in herpesviruses include a conserved core similar to the bacteriophage HK97 subunit. This core is often embellished with other domains such as the telokin Ig-like domain of phage P22
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Structural evolution of the P22-like phages: Comparison of Sf6 and P22 procapsid and virion architectures.
By admin, on March 9th, 2012
Metallomics. 2012 Mar 8;
Banerjee S, Parker Siburt CJ, Mistry S, Noto JM, Dearmond P, Fitzgerald MC, Lambert LA, Cornelissen CN, Crumbliss AL
Neisseria gonorrhoeae is an obligate pathogen that hijacks iron from the human iron transport protein, holo-transferrin (Fe(2)-Tf), by expressing TonB-dependent outer membrane receptor proteins, TbpA and TbpB. Homologous to other TonB-dependent outer membrane transporters, TbpA is thought to consist of a β-barrel with an N-terminal plug domain. Previous reports by our laboratories show that the sequence EIEYE in the plug domain is highly conserved among various bacterial species that express TbpA and plays a crucial role in iron utilization for gonococci. We hypothesize that this highly conserved EIEYE sequence in the TbpA plug, rich in hard oxygen donor groups, binds with Fe(3+) through the transport process across the outer membrane through the β-barrel. Sequestration of Fe(3+) by the TbpA-plug supports the paradigm that the ferric iron must always remain chelated and controlled throughout the transport process. In order to test this hypothesis here we describe the ability of both the recombinant wild-type plug, and three small peptides that encompass the sequence EIEYE of the plug, to bind Fe(3+). This is the first report of the expression/isolation of the recombinant wild-type TbpA plug. Although CD and SUPREX spectroscopies suggest that a non-native structure is observed for the recombinant plug, fluorescence quenching titrations indicate that the wild-type recombinant TbpA plug binds Fe (3+) with a conditional log K(d) = 7 at pH 7.5, with no evidence of binding at pH 6.3. A recombinant TbpA plug with mutated sequence (NEIEYEN → NEIAAAN) shows no evidence of Fe(3+) binding under our experimental set up. Interestingly, in silico modeling with the wild-type plug also predicts a flexible loop structure for the EIEYE sequence under native conditions which once again supports the Fe(3+) binding hypothesis. These in vitro observations are consistent with the hypothesis that the EIEYE sequence in the wild-type TbpA plug binds Fe(3+) during the outer membrane transport process in vivo.
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Evidence of Fe(3+) interaction with the plug domain of the outer membrane transferrin receptor protein of Neisseria gonorrhoeae: implications for Fe transport.
By admin, on March 5th, 2012
Biochem J . 2012 Feb 27; Silva LP, Yu RH, Calmettes C, Yang X, Moraes TF, Schriemer DC, Schryvers AB The ability to acquire iron directly from host transferrin (Tf) is an adaptation common to important bacterial pathogens belonging to the Pasteurellaceae, Moraxellaceae and Neisseriaceae families.
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Steric and allosteric factors prevent simultaneous binding of transferrin-binding proteins A and B to transferrin.
By admin, on March 5th, 2012
Biochem J . 2012 Feb 27; Silva LP, Yu RH, Calmettes C, Yang X, Moraes TF, Schriemer DC, Schryvers AB The ability to acquire iron directly from host transferrin (Tf) is an adaptation common to important bacterial pathogens belonging to the Pasteurellaceae, Moraxellaceae and Neisseriaceae families. A surface receptor comprised of an integral outer membrane protein, TbpA (transferrin binding protein A) and a surface exposed lipoprotein, TbpB, mediates the iron acquisition process
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Steric and allosteric factors prevent simultaneous binding of transferrin-binding proteins A and B to transferrin.
By admin, on March 3rd, 2012
Mol Microbiol. 2012 Mar 2;
Li G, Young KD
Several bacterial structures, processes and proteins are localized primarily to the poles of rod shaped cells. To better understand this cellular organization, we devised a new method for identifying proteins that localize to the poles of Escherichia coli. Pole-derived membrane fragments were isolated by affinity capture of vesicles containing the chemotaxis protein, Tar; and for comparison, vesicles representing all parts of the cytoplasmic membrane were captured by expressing a Tar variant that was no longer pole-specific. A combination of one-dimensional SDS-PAGE and semi-quantitative mass spectrometry identified 31 proteins that were highly enriched in polar vesicles. Five were chemotaxis proteins known to be pole-specific and another, Aer, was an aerotaxis protein that had not yet been localized to the pole. The behavior of these internal controls validated the overall approach. GFP-fused derivatives of four candidates (Aer, YqjD, TnaA and GroES) formed polar foci that were distinct from inclusion bodies. TnaA-GFP and GroES-GFP were functional, formed a single focus per cell, and competed for polar localization with the wild type versions of these proteins. Polar localization of TnaA, GroES and YqjD was disrupted in cells lacking the MinCDE proteins, suggesting that this system may help localize proteins not involved in cell division. © 2012 Blackwell Publishing Ltd.
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Isolation and identification of new inner membrane-associated proteins that localize to cell poles in Escherichia coli.
By admin, on March 1st, 2012
J Biol Chem . 2012 Feb 27; Durand E, Zoued A, Spinelli S, Watson PJ, Aschtgen MS, Journet L, Cambillau C, Cascales E The type VI secretion system (T6SS)4 is a macromolecular system distributed in Gram negative bacteria, responsible for the secretion of effector proteins into target cells. The T6SS has a broad versatility as it can target both eukaryotic and prokaryotic cells
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Structural characterization and oligomerization of the TssL protein, a component shared by the bacterial Type VI and Type IVb secretion systems.
By admin, on March 1st, 2012
J Biol Chem . 2012 Feb 27; Durand E, Zoued A, Spinelli S, Watson PJ, Aschtgen MS, Journet L, Cambillau C, Cascales E The type VI secretion system (T6SS)4 is a macromolecular system distributed in Gram negative bacteria, responsible for the secretion of effector proteins into target cells. The T6SS has a broad versatility as it can target both eukaryotic and prokaryotic cells.
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Structural characterization and oligomerization of the TssL protein, a component shared by the bacterial Type VI and Type IVb secretion systems.
By admin, on March 1st, 2012
J Biol Chem . 2012 Feb 27; Durand E, Zoued A, Spinelli S, Watson PJ, Aschtgen MS, Journet L, Cambillau C, Cascales E The type VI secretion system (T6SS)4 is a macromolecular system distributed in Gram negative bacteria, responsible for the secretion of effector proteins into target cells.
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Structural characterization and oligomerization of the TssL protein, a component shared by the bacterial Type VI and Type IVb secretion systems.
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