Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the complete genome sequence of yersinia pseudotuberculosis ip31758, the causative agent of far east scarlet-like fever. | the first reported far east scarlet-like fever (feslf) epidemic swept the pacific coastal region of russia in the late 1950s. symptoms of the severe infection included erythematous skin rash and desquamation, exanthema, hyperhemic tongue, and a toxic shock syndrome. the term feslf was coined for the infection because it shares clinical presentations with scarlet fever caused by group a streptococci. the causative agent was later identified as yersinia pseudotuberculosis, although the range of mo ... | 2007 | 17784789 |
| siderophore-based iron acquisition and pathogen control. | high-affinity iron acquisition is mediated by siderophore-dependent pathways in the majority of pathogenic and nonpathogenic bacteria and fungi. considerable progress has been made in characterizing and understanding mechanisms of siderophore synthesis, secretion, iron scavenging, and siderophore-delivered iron uptake and its release. the regulation of siderophore pathways reveals multilayer networks at the transcriptional and posttranscriptional levels. due to the key role of many siderophores ... | 2007 | 17804665 |
| evaluation of reference genes for real-time rt-pcr expression studies in the plant pathogen pectobacterium atrosepticum. | real-time rt-pcr has become a powerful technique to monitor low-abundance mrna expression and is a useful tool when examining bacterial gene expression inside infected host tissues. however, correct evaluation of data requires accurate and reliable normalisation against internal standards. thus, the identification of reference genes whose expression does not change during the course of the experiment is of paramount importance. here, we present a study where manipulation of cultural growth condi ... | 2007 | 17888160 |
| compromised outer membrane integrity in vibrio cholerae type ii secretion mutants. | the type ii secretion (t2s) system of vibrio cholerae is a multiprotein complex that spans the cell envelope and secretes proteins important for pathogenesis as well as survival in different environments. here we report that, in addition to the loss of extracellular secretion, removal or inhibition of expression of the t2s genes, epsc-n, results in growth defects and a broad range of alterations in the outer membrane that interfere with its barrier function. specifically, the sensitivity to memb ... | 2007 | 17890307 |
| alternate slya and h-ns nucleoprotein complexes control hlye expression in escherichia coli k-12. | haemolysin e is a cytolytic pore-forming toxin found in several escherichia coli and salmonella enterica strains. expression of hlye is repressed by the global regulator h-ns (histone-like nucleoid structuring protein), but can be activated by the regulator slya. expression of a chromosomal hlye-lacz fusion in an e. coli slya mutant was reduced to 60% of the wild-type level confirming a positive role for slya. dnase i footprint analysis revealed the presence of two separate slya binding sites, o ... | 2007 | 17892462 |
| metal ion-dependent, reversible, protein filament formation by designed beta-roll polypeptides. | a right-handed, calcium-dependent beta-roll structure found in secreted proteases and repeat-in-toxin proteins was used as a template for the design of minimal, soluble, monomeric polypeptides that would fold in the presence of ca2+. two polypeptides were synthesised to contain two and four metal-binding sites, respectively, and exploit stacked tryptophan pairs to stabilise the fold and report on the conformational state of the polypeptide. | 2007 | 17908326 |
| projection maps of three members of the kdgm outer membrane protein family. | we present the projection structures of the three outer membrane porins kdgm and kdgn from erwinia chrysanthemi and nanc from escherichia coli, based on 2d electron crystallography. a wide screening of 2d crystallization conditions yielded tubular crystals of a suitable size and quality to perform high-resolution electron microscopy. data processing of untilted samples allowed us to separate the information of the two crystalline layers and resulted in projection maps to a resolution of up to 7a ... | 2007 | 17919922 |
| multiple superoxide dismutases in agrobacterium tumefaciens: functional analysis, gene regulation, and influence on tumorigenesis. | agrobacterium tumefaciens possesses three iron-containing superoxide dismutases (fesods) encoded by distinct genes with differential expression patterns. sodbi and sodbii are cytoplasmic isozymes, while sodbiii is a periplasmic isozyme. sodbi is expressed at a high levels throughout all growth phases. sodbii expression is highly induced upon exposure to superoxide anions in a soxr-dependent manner. sodbiii is expressed only during stationary phase. analysis of the physiological function of sods ... | 2007 | 17921294 |
| mapping critical interactive sites within the periplasmic domain of the vibrio cholerae type ii secretion protein epsm. | the type ii secretion (t2s) system is present in many gram-negative species, both pathogenic and nonpathogenic, where it supports the delivery of a variety of toxins, proteases, and lipases into the extracellular environment. in vibrio cholerae, the t2s apparatus is composed of 12 eps proteins that assemble into a multiprotein complex that spans the entire cell envelope. two of these proteins, epsm and epsl, are key components of the secretion machinery present in the inner membrane. in addition ... | 2007 | 17921296 |
| erwinia carotovora elicitors and botrytis cinerea activate defense responses in physcomitrella patens. | vascular plants respond to pathogens by activating a diverse array of defense mechanisms. studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. however, very little is known about the infection and defense responses of the bryophyte, physcomitrella patens, to well-studied phytopathogens. the purpose of this study was to determine: i) whether two representative broad host range pathogens, erwinia carot ... | 2007 | 17922917 |
| comparative and functional genomics reveals genetic diversity and determinants of host specificity among reference strains and a large collection of chinese isolates of the phytopathogen xanthomonas campestris pv. campestris. | xanthomonas campestris pathovar campestris (xcc) is the causal agent of black rot disease of crucifers worldwide. the molecular genetic diversity and host specificity of xcc are poorly understood. | 2007 | 17927820 |
| increased catalytic efficiency following gene fusion of bifunctional methionine sulfoxide reductase enzymes from shewanella oneidensis. | methionine sulfoxide reductase enzymes msra and msrb have complementary stereospecificities that reduce the s and r stereoisomers of methionine sulfoxide (metso), respectively, and together function as critical antioxidant enzymes. in some pathogenic and metal-reducing bacteria, these genes are fused to form a bifunctional methionine sulfoxide reductase (i.e., msrba) enzyme. to investigate how gene fusion affects the substrate specificity and catalytic activities of msr, we have cloned and expre ... | 2007 | 17997579 |
| enteropathogen resource integration center (eric): bioinformatics support for research on biodefense-relevant enterobacteria. | eric, the enteropathogen resource integration center (www.ericbrc.org), is a new web portal serving as a rich source of information about enterobacteria on the niaid established list of select agents related to biodefense-diarrheagenic escherichia coli, shigella spp., salmonella spp., yersinia enterocolitica and yersinia pestis. more than 30 genomes have been completely sequenced, many more exist in draft form and additional projects are underway. these organisms are increasingly the focus of st ... | 2008 | 17999997 |
| enteropathogen resource integration center (eric): bioinformatics support for research on biodefense-relevant enterobacteria. | eric, the enteropathogen resource integration center (www.ericbrc.org), is a new web portal serving as a rich source of information about enterobacteria on the niaid established list of select agents related to biodefense-diarrheagenic escherichia coli, shigella spp., salmonella spp., yersinia enterocolitica and yersinia pestis. more than 30 genomes have been completely sequenced, many more exist in draft form and additional projects are underway. these organisms are increasingly the focus of st ... | 2008 | 17999997 |
| the crystal structure of a binary complex of two pseudopilins: epsi and epsj from the type 2 secretion system of vibrio vulnificus. | type ii secretion systems (t2ss) translocate virulence factors from the periplasmic space of many pathogenic bacteria into the extracellular environment. the t2ss of vibrio cholerae and related species is called the extracellular protein secretion (eps) system that consists of a core of multiple copies of 11 different proteins. the pseudopilins, epsg, epsh, epsi, epsj and epsk, are five t2ss proteins that are thought to assemble into a pseudopilus, which is assumed to interact with the outer mem ... | 2008 | 18022192 |
| the crystal structure of a binary complex of two pseudopilins: epsi and epsj from the type 2 secretion system of vibrio vulnificus. | type ii secretion systems (t2ss) translocate virulence factors from the periplasmic space of many pathogenic bacteria into the extracellular environment. the t2ss of vibrio cholerae and related species is called the extracellular protein secretion (eps) system that consists of a core of multiple copies of 11 different proteins. the pseudopilins, epsg, epsh, epsi, epsj and epsk, are five t2ss proteins that are thought to assemble into a pseudopilus, which is assumed to interact with the outer mem ... | 2008 | 18022192 |
| the dna nucleoid-associated protein fis co-ordinates the expression of the main virulence genes in the phytopathogenic bacterium erwinia chrysanthemi. | erwinia chrysanthemi strain 3937 is a necrotrophic bacterial plant pathogen. pectinolytic enzymes and, in particular, pectate lyases (pels) play a key role in soft rot symptoms but the efficient colonization of plants by e. chrysanthemi requires additional factors. these factors include the harpin hrpn, the cellulase cel5, proteases (prts), flagellar proteins and the sap system, involved in the detoxification of plant antimicrobial peptides. hrpn and flagellum are mostly involved in the early st ... | 2007 | 18028311 |
| integration of two essential virulence modulating signals at the erwinia chrysanthemi pel gene promoters: a role for fis in the growth-phase regulation. | production of the essential virulence factors, called pectate lyases (pels), in the phytopathogenic bacterium erwinia chrysanthemi is controlled by a complex regulation system and responds to various stimuli, such as the presence of pectin or plant extracts, growth phase, temperature and iron concentration. the presence of pectin and growth phase are the most important signals identified. eight regulators modulating the expression of the pel genes (encoding pels) have been characterized. these r ... | 2007 | 18028312 |
| [in process citation]. | the cure rate for children with acute lymphoblastic leukaemia (all) has increased to approximately 70%, in part related to the use of the protein synthesis inhibitor drug asparaginase in multiagent chemotherapy regimens. its lack of haematological toxicity allows its incorporation into phases of therapy in which myelosuppression would be expected either from the disease itself (induction therapy) or secondary to other chemotherapeutic agents (consolidation, intensification or reinduction phases ... | 1997 | 18031078 |
| protein crystallography for non-crystallographers, or how to get the best (but not more) from published macromolecular structures. | the number of macromolecular structures deposited in the protein data bank now exceeds 45,000, with the vast majority determined using crystallographic methods. thousands of studies describing such structures have been published in the scientific literature, and 14 nobel prizes in chemistry or medicine have been awarded to protein crystallographers. as important as these structures are for understanding the processes that take place in living organisms and also for practical applications such as ... | 2007 | 18034855 |
| protein crystallography for non-crystallographers, or how to get the best (but not more) from published macromolecular structures. | the number of macromolecular structures deposited in the protein data bank now exceeds 45,000, with the vast majority determined using crystallographic methods. thousands of studies describing such structures have been published in the scientific literature, and 14 nobel prizes in chemistry or medicine have been awarded to protein crystallographers. as important as these structures are for understanding the processes that take place in living organisms and also for practical applications such as ... | 2007 | 18034855 |
| the heterologous expression of polysaccharidase-encoding genes with oenological relevance in saccharomyces cerevisiae. | the main objective of this study was to develop polysaccharide-degrading wine strains of saccharomyces cerevisiae, which are able to improve aspects of wine processing and clarification, as well as colour extraction and stabilization during winemaking. | 2007 | 18045408 |
| dynamic regulation of gaca in type iii secretion, pectinase gene expression, pellicle formation, and pathogenicity of dickeya dadantii (erwinia chrysanthemi 3937). | dickeya dadantii (erwinia chrysanthemi 3937) secretes exoenzymes, including pectin-degrading enzymes, leading to the loss of structural integrity of plant cell walls. a type iii secretion system (t3ss) is essential for full virulence of this bacterium within plant hosts. the gacs/gaca two-component signal transduction system participates in important biological roles in several gram-negative bacteria. in this study, a gaca deletion mutant (ech137) of d. dadantii was constructed to investigate th ... | 2008 | 18052890 |
| the role of horizontal transfer in the evolution of a highly variable lipopolysaccharide biosynthesis locus in xanthomonads that infect rice, citrus and crucifers. | lipopolysaccharide (lps) is a pathogen associated molecular pattern (pamp) of animal and plant pathogenic bacteria. variation at the interstrain level is common in lps biosynthetic gene clusters of animal pathogenic bacteria. this variation has been proposed to play a role in evading the host immune system. even though lps is a modulator of plant defense responses, reports of interstrain variation in lps gene clusters of plant pathogenic bacteria are rare. | 2007 | 18053269 |
| the acyl-homoserine lactone-type quorum-sensing system modulates cell motility and virulence of erwinia chrysanthemi pv. zeae. | erwinia chrysanthemi pv. zeae is one of the erwinia chrysanthemi pathovars that infects on both dicotyledons and monocotyledons. however, little is known about the molecular basis and regulatory mechanisms of its virulence. by using a transposon mutagenesis approach, we cloned the genes coding for an e. chrysanthemi pv. zeae synthase of acyl-homoserine lactone (ahl) quorum-sensing signals (expi(ecz)) and a cognate response regulator (expr(ecz)). chromatography analysis showed that expi(ecz) enco ... | 2008 | 18083823 |
| the acyl-homoserine lactone-type quorum-sensing system modulates cell motility and virulence of erwinia chrysanthemi pv. zeae. | erwinia chrysanthemi pv. zeae is one of the erwinia chrysanthemi pathovars that infects on both dicotyledons and monocotyledons. however, little is known about the molecular basis and regulatory mechanisms of its virulence. by using a transposon mutagenesis approach, we cloned the genes coding for an e. chrysanthemi pv. zeae synthase of acyl-homoserine lactone (ahl) quorum-sensing signals (expi(ecz)) and a cognate response regulator (expr(ecz)). chromatography analysis showed that expi(ecz) enco ... | 2008 | 18083823 |
| cta4 transcription factor mediates induction of nitrosative stress response in candida albicans. | this work has identified regulatory elements in the major fungal pathogen candida albicans that enable response to nitrosative stress. nitric oxide (no) is generated by macrophages of the host immune system and commensal bacteria, and the ability to resist its toxicity is one adaptation that promotes survival of c. albicans inside the human body. exposing c. albicans to no induces upregulation of the flavohemoglobin yhb1p. this protein confers protection by enzymatically converting no to harmles ... | 2008 | 18083829 |
| cta4 transcription factor mediates induction of nitrosative stress response in candida albicans. | this work has identified regulatory elements in the major fungal pathogen candida albicans that enable response to nitrosative stress. nitric oxide (no) is generated by macrophages of the host immune system and commensal bacteria, and the ability to resist its toxicity is one adaptation that promotes survival of c. albicans inside the human body. exposing c. albicans to no induces upregulation of the flavohemoglobin yhb1p. this protein confers protection by enzymatically converting no to harmles ... | 2008 | 18083829 |
| the intracellular pathogen rhodococcus equi produces a catecholate siderophore required for saprophytic growth. | little is known about the iron acquisition systems of the soilborne facultative intracellular pathogen rhodococcus equi. we previously reported that expression of iupabc, encoding a putative siderophore abc transporter system, is iron regulated and required for growth at low iron concentrations. here we show that disruption of iupa leads to the concomitant accumulation of catecholates and a chromophore with absorption maxima at 341 and 528 nm during growth under iron-replete conditions. in contr ... | 2008 | 18156254 |
| the intracellular pathogen rhodococcus equi produces a catecholate siderophore required for saprophytic growth. | little is known about the iron acquisition systems of the soilborne facultative intracellular pathogen rhodococcus equi. we previously reported that expression of iupabc, encoding a putative siderophore abc transporter system, is iron regulated and required for growth at low iron concentrations. here we show that disruption of iupa leads to the concomitant accumulation of catecholates and a chromophore with absorption maxima at 341 and 528 nm during growth under iron-replete conditions. in contr ... | 2008 | 18156254 |
| pseudomonas syringae bett is a low-affinity choline transporter that is responsible for superior osmoprotection by choline over glycine betaine. | the plant pathogen pseudomonas syringae derives better osmoprotection from choline than from glycine betaine, unlike most bacteria that have been characterized. in this report, we identified a betaine/carnitine/choline family transporter (bcct) in p. syringae pv. tomato strain dc3000 that mediates the transport of choline and acetylcholine. this transporter has a particularly low affinity (k(m) of 876 microm) and high capacity (v(max) of 80 nmol/min/mg of protein) for choline transport relative ... | 2008 | 18156257 |
| pseudomonas syringae bett is a low-affinity choline transporter that is responsible for superior osmoprotection by choline over glycine betaine. | the plant pathogen pseudomonas syringae derives better osmoprotection from choline than from glycine betaine, unlike most bacteria that have been characterized. in this report, we identified a betaine/carnitine/choline family transporter (bcct) in p. syringae pv. tomato strain dc3000 that mediates the transport of choline and acetylcholine. this transporter has a particularly low affinity (k(m) of 876 microm) and high capacity (v(max) of 80 nmol/min/mg of protein) for choline transport relative ... | 2008 | 18156257 |
| improvement of the thermostability and activity of a pectate lyase by single amino acid substitutions, using a strategy based on melting-temperature-guided sequence alignment. | in the vast number of random mutagenesis experiments that have targeted protein thermostability, single amino acid substitutions that increase the apparent melting temperature (tm) of the enzyme more than 1 to 2 degrees c are rare and often require the creation of a large library of mutated genes. here we present a case where a single beneficial mutation (r236f) of a hemp fiber-processing pectate lyase of xanthomonas campestris origin (pl(xc)) produced a 6 degrees c increase in tm and a 23-fold ... | 2008 | 18156340 |
| improvement of the thermostability and activity of a pectate lyase by single amino acid substitutions, using a strategy based on melting-temperature-guided sequence alignment. | in the vast number of random mutagenesis experiments that have targeted protein thermostability, single amino acid substitutions that increase the apparent melting temperature (tm) of the enzyme more than 1 to 2 degrees c are rare and often require the creation of a large library of mutated genes. here we present a case where a single beneficial mutation (r236f) of a hemp fiber-processing pectate lyase of xanthomonas campestris origin (pl(xc)) produced a 6 degrees c increase in tm and a 23-fold ... | 2008 | 18156340 |
| the complete genome sequence and analysis of the epsilonproteobacterium arcobacter butzleri. | arcobacter butzleri is a member of the epsilon subdivision of the proteobacteria and a close taxonomic relative of established pathogens, such as campylobacter jejuni and helicobacter pylori. here we present the complete genome sequence of the human clinical isolate, a. butzleri strain rm4018. | 2007 | 18159241 |
| differential role of ferritins in iron metabolism and virulence of the plant-pathogenic bacterium erwinia chrysanthemi 3937. | during infection, the phytopathogenic enterobacterium erwinia chrysanthemi has to cope with iron-limiting conditions and the production of reactive oxygen species by plant cells. previous studies have shown that a tight control of the bacterial intracellular iron content is necessary for full virulence. the e. chrysanthemi genome possesses two loci that could be devoted to iron storage: the bfr gene, encoding a heme-containing bacterioferritin, and the ftna gene, coding for a paradigmatic ferrit ... | 2008 | 18165304 |
| differential role of ferritins in iron metabolism and virulence of the plant-pathogenic bacterium erwinia chrysanthemi 3937. | during infection, the phytopathogenic enterobacterium erwinia chrysanthemi has to cope with iron-limiting conditions and the production of reactive oxygen species by plant cells. previous studies have shown that a tight control of the bacterial intracellular iron content is necessary for full virulence. the e. chrysanthemi genome possesses two loci that could be devoted to iron storage: the bfr gene, encoding a heme-containing bacterioferritin, and the ftna gene, coding for a paradigmatic ferrit ... | 2008 | 18165304 |
| a legionella pneumophila peptidyl-prolyl cis-trans isomerase present in culture supernatants is necessary for optimal growth at low temperatures. | several legionella pneumophila proteins were highly expressed in low-temperature supernatants. one of these proteins was the peptidyl-prolyl isomerase ppib. mutants lacking ppib exhibited reduced growth at 17 degrees c. since ppib lacked a signal sequence and was present in 17 degrees c supernatants of type ii and type iv secretion mutants, this protein may be secreted by a novel mechanism. | 2008 | 18165359 |
| a legionella pneumophila peptidyl-prolyl cis-trans isomerase present in culture supernatants is necessary for optimal growth at low temperatures. | several legionella pneumophila proteins were highly expressed in low-temperature supernatants. one of these proteins was the peptidyl-prolyl isomerase ppib. mutants lacking ppib exhibited reduced growth at 17 degrees c. since ppib lacked a signal sequence and was present in 17 degrees c supernatants of type ii and type iv secretion mutants, this protein may be secreted by a novel mechanism. | 2008 | 18165359 |
| the gaca global regulator is required for the appropriate expression of erwinia chrysanthemi 3937 pathogenicity genes during plant infection. | pathogenicity of the phytopathogenic enterobacterium erwinia chrysanthemi, the causal agent of soft rot disease on many plants, is a complex process involving several factors whose production is regulated by a complex, intertwined regulatory network. in this work we characterized the gaca regulator, member of the gacs-gaca two-component system, as a global regulator which is required for disease expression but not for bacterial multiplication in planta during the first stages of the plant infect ... | 2008 | 18177376 |
| role and regulation of iron-sulfur cluster biosynthesis genes in shigella flexneri virulence. | shigella flexneri, a causative agent of bacterial dysentery, possesses two predicted iron-sulfur cluster biosynthesis systems called suf and isc. s. flexneri strains containing deletion mutations in the entire suf operon (ur011) or the iscsua genes (ur022) were constructed. both mutants were defective in surviving exposure to oxidative stress. the suf mutant showed growth that was comparable to that of the parental strain in both iron-replete and iron-limiting media; however, the isc mutant show ... | 2008 | 18195027 |
| complicated catheter-associated urinary tract infections due to escherichia coli and proteus mirabilis. | catheter-associated urinary tract infections (cautis) represent the most common type of nosocomial infection and are a major health concern due to the complications and frequent recurrence. these infections are often caused by escherichia coli and proteus mirabilis. gram-negative bacterial species that cause cautis express a number of virulence factors associated with adhesion, motility, biofilm formation, immunoavoidance, and nutrient acquisition as well as factors that cause damage to the host ... | 2008 | 18202436 |
| the xanthomonas oryzae pv. oryzae phopq two-component system is required for avrxa21 activity, hrpg expression, and virulence. | the rice pathogen recognition receptor, xa21, confers resistance to xanthomonas oryzae pv. oryzae strains producing the type one system-secreted molecule, avrxa21. x. oryzae pv. oryzae requires a regulatory two-component system (tcs) called raxrh to regulate expression of eight rax (required for avrxa21 activity) genes and to sense population cell density. to identify other key components in this critical regulatory circuit, we assayed proteins expressed in a raxr gene knockout strain. this surv ... | 2008 | 18203830 |
| the iron stimulon of xylella fastidiosa includes genes for type iv pilus and colicin v-like bacteriocins. | xylella fastidiosa is the etiologic agent of a wide range of plant diseases, including citrus variegated chlorosis (cvc), a major threat to citrus industry. the genomes of several strains of this phytopathogen were completely sequenced, enabling large-scale functional studies. dna microarrays representing 2,608 (91.6%) coding sequences (cds) of x. fastidiosa cvc strain 9a5c were used to investigate transcript levels during growth with different iron availabilities. when treated with the iron che ... | 2008 | 18223091 |
| comparative secretome analysis suggests low plant cell wall degrading capacity in frankia symbionts. | frankia sp. strains, the nitrogen-fixing facultative endosymbionts of actinorhizal plants, have long been proposed to secrete hydrolytic enzymes such as cellulases, pectinases, and proteases that may contribute to plant root penetration and formation of symbiotic root nodules. these or other secreted proteins might logically be involved in the as yet unknown molecular interactions between frankia and their host plants. we compared the genome-based secretomes of three frankia strains representing ... | 2008 | 18226217 |
| identification of protein secretion systems and novel secreted proteins in rhizobium leguminosarum bv. viciae. | proteins secreted by bacteria play an important role in infection of eukaryotic hosts. rhizobia infect the roots of leguminous plants and establish a mutually beneficial symbiosis. proteins secreted during the infection process by some rhizobial strains can influence infection and modify the plant defence signalling pathways. the aim of this study was to systematically analyse protein secretion in the recently sequenced strain rhizobium leguminosarum bv. viciae 3841. | 2008 | 18230162 |
| structure of the minor pseudopilin epsh from the type 2 secretion system of vibrio cholerae. | many gram-negative bacteria use the multi-protein type ii secretion system (t2ss) to selectively translocate virulence factors from the periplasmic space into the extracellular environment. in vibrio cholerae the t2ss is called the extracellular protein secretion (eps) system,which translocates cholera toxin and several enzymes in their folded state across the outer membrane. five proteins of the t2ss, the pseudopilins, are thought to assemble into a pseudopilus, which may control the outer memb ... | 2008 | 18241884 |
| structure of the minor pseudopilin epsh from the type 2 secretion system of vibrio cholerae. | many gram-negative bacteria use the multi-protein type ii secretion system (t2ss) to selectively translocate virulence factors from the periplasmic space into the extracellular environment. in vibrio cholerae the t2ss is called the extracellular protein secretion (eps) system,which translocates cholera toxin and several enzymes in their folded state across the outer membrane. five proteins of the t2ss, the pseudopilins, are thought to assemble into a pseudopilus, which may control the outer memb ... | 2008 | 18241884 |
| biogenesis of fe/s proteins and pathogenicity: iscr plays a key role in allowing erwinia chrysanthemi to adapt to hostile conditions. | the erwinia chrysanthemi genome is predicted to encode three systems, nif, isc and suf, known to assist fe/s cluster biogenesis and the csdae cysteine desulphurase. single iscu, hsca and fdx mutants were found sensitive to paraquat and exhibited reduced virulence on both chicory leaves and arabidopsis thaliana. depletion of the whole isc system led to a pleiotropic phenotype, including sensitivity to both paraquat and 2,2'-dipyridyl, auxotrophies for branched-chain amino acids, thiamine, nicotin ... | 2008 | 18284573 |
| interactions between food-borne pathogens and protozoa isolated from lettuce and spinach. | the survival of salmonella enterica was recently shown to increase when the bacteria were sequestered in expelled food vacuoles (vesicles) of tetrahymena. because fresh produce is increasingly linked to outbreaks of enteric illness, the present investigation aimed to determine the prevalence of protozoa on spinach and lettuce and to examine their interactions with s. enterica, escherichia coli o157:h7, and listeria monocytogenes. glaucoma sp., colpoda steinii, and acanthamoeba palestinensis were ... | 2008 | 18310421 |
| x-ray structure of a prokaryotic pentameric ligand-gated ion channel. | pentameric ligand-gated ion channels (plgics) are key players in the early events of electrical signal transduction at chemical synapses. the family codes for a structurally conserved scaffold of channel proteins that open in response to the binding of neurotransmitter molecules. all proteins share a pentameric organization of identical or related subunits that consist of an extracellular ligand-binding domain followed by a transmembrane channel domain. the nicotinic acetylcholine receptor (nach ... | 2008 | 18322461 |
| expression, purification, crystallization and preliminary x-ray analysis of the polysaccharide lyase rb5312 from the marine planctomycete rhodopirellula baltica. | polysaccharide lyases belonging to family pl1 act on pectins. these anionic polymers are usually produced by terrestrial plants and therefore pectinolytic enzymes are not frequently observed in marine microorganisms. the protein rb5312 from the marine bacterium rhodopirellula baltica is distantly related to family pl1 pectate lyases, but its exact function is unclear. in this study, the expression and purification of a recombinant form of rb5312 are described. this protein was crystallized using ... | 2008 | 18323615 |
| pepper pectin methylesterase inhibitor protein capmei1 is required for antifungal activity, basal disease resistance and abiotic stress tolerance. | pectin is one of the main components of the plant cell wall that functions as the primary barrier against pathogens. among the extracellular pectinolytic enzymes, pectin methylesterase (pme) demethylesterifies pectin, which is secreted into the cell wall in a highly methylesterified form. here, we isolated and functionally characterized the pepper (capsicum annuum l.) gene capmei1, which encodes a pectin methylesterase inhibitor protein (pmei), in pepper leaves infected by xanthomonas campestris ... | 2008 | 18327607 |
| disulfide bond isomerization in prokaryotes. | proteins with multiple cysteine residues often require disulfide isomerization reactions before they attain their correct conformation. in prokaryotes this reaction is catalyzed mainly by dsbc, a protein that shares many similarities in structure and mechanism to the eukaryotic protein disulfide isomerase. this review discusses the current knowledge about disulfide isomerization in prokaryotes. | 2008 | 18342631 |
| crystal structure of a functional dimer of the phoq sensor domain. | the phop-phoq two-component system is a well studied bacterial signaling system that regulates virulence and stress response. catalytic activity of the histidine kinase sensor protein phoq is activated by low extracellular concentrations of divalent cations such as mg2+, and subsequently the response regulator phop is activated in turn through a classic phosphotransfer pathway that is typical in such systems. the phoq sensor domains of enteric bacteria contain an acidic cluster of residues (eddd ... | 2008 | 18348979 |
| nitric oxide antagonizes the acid tolerance response that protects salmonella against innate gastric defenses. | reactive nitrogen species (rns) derived from dietary and salivary inorganic nitrogen oxides foment innate host defenses associated with the acidity of the stomach. the mechanisms by which these reactive species exert antimicrobial activity in the gastric lumen are, however, poorly understood. | 2008 | 18350168 |
| adhesion and retention of a bacterial phytopathogen erwinia chrysanthemi in biofilm-coated porous media. | the goal of this study is to investigate the impact of biofilm physical and biological properties on bacterial transport and deposition in porous media. experiments were performed in packed columns to examine the removal of erwinia chrysanthemi (ech3937), a phytopathogen, from the bulk fluid due to its attachmentto glass beads coated with pseudomonas aeruginosa biofilms. two isogenic p. aeruginosa strains, pao1 and pd0300, with different eps secretion capabilities and eps compositions, were used ... | 2008 | 18350891 |
| synthesis and biological activity of analogues of vanchrobactin, a siderophore from vibrio anguillarum serotype o2. | several analogues of vanchrobactin, a catechol siderophore isolated from the bacterial fish pathogen vibrio anguillarum serotype o2 strain rv22, have been synthesized. the biological evaluation of these novel compounds showed that most of them are active as siderophores, as determined by growth promotion assays using the producer strain, as well as v. anguillarum serotype o1, salmonella enterica, and erwinia chrysanthemi. these compounds also gave a positive chrome azurol-s (cas) test. on the ba ... | 2008 | 18362969 |
| characterization of the rnd-type multidrug efflux pump mexab-oprm of the plant pathogen pseudomonas syringae. | in gram-negative bacteria, transporters belonging to the rnd family are the transporters most relevant for resistance to antimicrobial compounds. in pseudomonas aeruginosa, a clinically important pathogen, the rnd-type pump mexab-oprm has been recognized as one of the major multidrug efflux systems. here, homologues of mexab-oprm in the plant pathogens pseudomonas syringae pv. phaseolicola 1448a, p. syringae pv. syringae b728a, and p. syringae pv. tomato dc3000 were identified, and mexab-oprm-de ... | 2008 | 18390672 |
| the crystal structure of pectate lyase peli from soft rot pathogen erwinia chrysanthemi in complex with its substrate. | the crystallographic structure of the family 3 polysaccharide lyase (pl-3) peli from erwinia chrysanthemi has been solved to 1.45 a resolution. it consists of an n-terminal domain harboring a fibronectin type iii fold linked to a catalytic domain displaying a parallel beta-helix topology. the n-terminal domain is located away from the active site and is not involved in the catalytic process. after secretion in planta, the two domains are separated by e. chrysanthemi proteases. this event turns o ... | 2008 | 18430740 |
| regulatory network controlling extracellular proteins in erwinia carotovora subsp. carotovora: flhdc, the master regulator of flagellar genes, activates rsmb regulatory rna production by affecting gaca and hexa (lrha) expression. | erwinia carotovora subsp. carotovora produces an array of extracellular proteins (i.e., exoproteins), including plant cell wall-degrading enzymes and harpin, an effector responsible for eliciting hypersensitive reaction. exoprotein genes are coregulated by the quorum-sensing signal, n-acyl homoserine lactone, plant signals, an assortment of transcriptional factors/regulators (gacs/a, expr1, expr2, kdgr, rpos, hexa, and rsmc) and posttranscriptional regulators (rsma, rsmb rna). rsmb rna productio ... | 2008 | 18441056 |
| chromosomal toxin-antitoxin systems may act as antiaddiction modules. | toxin-antitoxin (ta) systems are widespread among bacterial chromosomes and mobile genetic elements. although in plasmids ta systems have a clear role in their vertical inheritance by selectively killing plasmid-free daughter cells (postsegregational killing or addiction phenomenon), the physiological role of chromosomally encoded ones remains under debate. the assumption that chromosomally encoded ta systems are part of stress response networks and/or programmed cell death machinery has been ca ... | 2008 | 18441063 |
| genome sequence and rapid evolution of the rice pathogen xanthomonas oryzae pv. oryzae pxo99a. | xanthomonas oryzae pv. oryzae causes bacterial blight of rice (oryza sativa l.), a major disease that constrains production of this staple crop in many parts of the world. we report here on the complete genome sequence of strain pxo99a and its comparison to two previously sequenced strains, kacc10331 and maff311018, which are highly similar to one another. | 2008 | 18452608 |
| rhizobium cellulase celc2 is essential for primary symbiotic infection of legume host roots. | the rhizobia-legume, root-nodule symbiosis provides the most efficient source of biologically fixed ammonia fertilizer for agricultural crops. its development involves pathways of specificity, infectivity, and effectivity resulting from expressed traits of the bacterium and host plant. a key event of the infection process required for development of this root-nodule symbiosis is a highly localized, complete erosion of the plant cell wall through which the bacterial symbiont penetrates to establi ... | 2008 | 18458328 |
| structural determinants of ca2+ permeability and conduction in the human 5-hydroxytryptamine type 3a receptor. | cation-selective cysteine (cys)-loop transmitter-gated ion channels provide an important pathway for ca2+ entry into neurones. we examined the influence on ca2+ permeation of amino acids located at intra- and extracellular ends of the conduction pathway of the human 5-hydroxytryptamine type 3a (5-ht3a) receptor. mutation of cytoplasmic arginine residues 432, 436, and 440 to glutamine, aspartate, and alanine (the aligned residues of the human 5-ht3b subunit (yielding 5-ht3a(qda)) increased pca/pc ... | 2008 | 18474595 |
| the major facilitator superfamily-type transporter ymfe and the multidrug-efflux activator mta mediate bacillibactin secretion in bacillus subtilis. | high-affinity iron acquisition in bacillus subtilis is mediated via the bacillibactin catechole siderophore pathway. three of the four essential pathway steps, bacillibactin synthesis, fe-bacillibactin uptake, and fe-bacillibactin hydrolysis have been characterized previously. the functional and regulatory components for bacillibactin secretion, the second step of the siderophore pathway, remained unknown. in this study, the screening of a b. subtilis exporter mutant library led to the identific ... | 2008 | 18502870 |
| bioinformatic tools for inferring functional information from plant microarray data: tools for the first steps. | microarrays are a very powerful tool for quantifying the amount of rna in samples; however, their ability to query essentially every gene in a genome, which can number in the tens of thousands, presents analytical and interpretative problems. as a result, a variety of software and web-based tools have been developed to help with these issues. this article highlights and reviews some of the tools for the first steps in the analysis of a microarray study. we have tried for a balance between free a ... | 2008 | 18528524 |
| the phoq histidine kinases of salmonella and pseudomonas spp. are structurally and functionally different: evidence that ph and antimicrobial peptide sensing contribute to mammalian pathogenesis. | the phoq sensor kinase is essential for salmonella typhimurium virulence for animals, and a homologue exists in the environmental organism and opportunistic pathogen pseudomonas aeruginosa. s. typhimurium phoq (st-phoq) is repressed by millimolar concentrations of divalent cations and activated by antimicrobial peptides and at acidic ph. st-phoq has a periplasmic per-arnt-sim domain, a fold commonly employed for ligand binding. however, substrate binding is instead accomplished by an acidic patc ... | 2008 | 18532985 |
| structural biology of pectin degradation by enterobacteriaceae. | summary: pectin is a structural polysaccharide that is integral for the stability of plant cell walls. during soft rot infection, secreted virulence factors from pectinolytic bacteria such as erwinia spp. degrade pectin, resulting in characteristic plant cell necrosis and tissue maceration. catabolism of pectin and its breakdown products by pectinolytic bacteria occurs within distinct cellular environments. this process initiates outside the cell, continues within the periplasmic space, and culm ... | 2008 | 18535148 |
| insights into plant cell wall degradation from the genome sequence of the soil bacterium cellvibrio japonicus. | the plant cell wall, which consists of a highly complex array of interconnecting polysaccharides, is the most abundant source of organic carbon in the biosphere. microorganisms that degrade the plant cell wall synthesize an extensive portfolio of hydrolytic enzymes that display highly complex molecular architectures. to unravel the intricate repertoire of plant cell wall-degrading enzymes synthesized by the saprophytic soil bacterium cellvibrio japonicus, we sequenced and analyzed its genome, wh ... | 2008 | 18556790 |
| dsba plays a critical and multifaceted role in the production of secreted virulence factors by the phytopathogen erwinia carotovora subsp. atroseptica. | erwinia carotovora subsp. atroseptica is an enterobacterial phytopathogen causing economically significant soft rot disease. pathogenesis is mediated by multiple secreted virulence factors, many of which are secreted by the type ii (out) secretion system. dsba catalyzes the introduction of disulfide bonds into periplasmic and secreted proteins. in this study, the extracellular proteome (secretome) of wild type e. carotovora subsp. atroseptica scri1043, and dsba and out mutants, was analyzed by s ... | 2008 | 18562317 |
| quorum sensing coordinates brute force and stealth modes of infection in the plant pathogen pectobacterium atrosepticum. | quorum sensing (qs) in vitro controls production of plant cell wall degrading enzymes (pcwdes) and other virulence factors in the soft rotting enterobacterial plant pathogen pectobacterium atrosepticum (pba). here, we demonstrate the genome-wide regulatory role of qs in vivo during the pba-potato interaction, using a pba-specific microarray. we show that 26% of the pba genome exhibited differential transcription in a qs (expi-) mutant, compared to the wild-type, suggesting that qs may make a gre ... | 2008 | 18566662 |
| the compatible-solute-binding protein opuac from bacillus subtilis: ligand binding, site-directed mutagenesis, and crystallographic studies. | in the soil bacterium bacillus subtilis, five transport systems work in concert to mediate the import of various compatible solutes that counteract the deleterious effects of increases in the osmolarity of the environment. among these five systems, the abc transporter opua, which catalyzes the import of glycine betaine and proline betaine, has been studied in detail in the past. here, we demonstrate that opua is capable of importing the sulfobetaine dimethylsulfonioacetate (dmsa). since opua is ... | 2008 | 18567662 |
| [genetic and molecular characters of toxin producing erwinia chrysanthemi pv. zeae]. | bacterial foot rot, caused by erwinia chrysanthemi pv. zeae, is one of the most important diseases in rice. genetic and molecular characters of toxin producting for erwinia chrysanthemi pv. zeae were conducted in this paper. | 2008 | 18590228 |
| comparative analysis of the glg operons of pectobacterium chrysanthemi py35 and other prokaryotes. | a chromosomal region of pectobacterium chrysanthemi py35 that contains of genes for glycogen synthesis was isolated from a cosmid library. the operon consists of glycogen branching enzyme (glgb), glycogen debranching enzyme (glgx), adp-glucose pyrophosphorylase (glgc), glycogen synthase (glga), and glycogen phosphorylase (glgp) genes. gene organization is similar to that of escherichia coli. the purified adp-glucose pyrophosphorylase (glgc) was activated by fructose 1,6-bisphosphate and inhibite ... | 2008 | 18594899 |
| bacterial apbc can bind and effectively transfer iron-sulfur clusters. | the metabolism of iron-sulfur ([fe-s]) clusters requires a complex set of machinery that is still being defined. mutants of salmonella enterica lacking apbc have nutritional and biochemical properties indicative of defects in [fe-s] cluster metabolism. apbc is a 40.8 kda homodimeric atpase and as purified contains little iron and no acid-labile sulfide. an [fe-s] cluster was reconstituted on apbc, generating a protein that bound 2 mol of fe and 2 mol of s (2-) per apbc monomer and had a uv-visib ... | 2008 | 18616280 |
| in vitro multimerization and membrane insertion of bacterial outer membrane secretin puld. | synthesis of the klebsiella oxytoca outer membrane secretin puld, or its membrane-associated core domain, in a liposome-supplemented escherichia coli in vitro transcription-translation system resulted in the formation of multimers that appeared as typical dodecameric secretin rings when examined by negative-stain electron microscopy. cryo-electron microscopy of unstained liposomes and differential extraction by urea indicated that the secretin particles were inserted into the liposome membranes. ... | 2008 | 18616949 |
| purification of an l-asparaginase-atrial natriuretic peptide fusion protein expressed in escherichia coli. | a novel fusion protein designed to facilitate protein purification was expressed in escherichia coli and purified separately by two different chromatography methods. l-asparaginase from erwinia chrysanthemi is fused to the n-terminus of a model peptide, alpha-human atrial natriuretic peptide (alpha-hanp). l-asparaginase was chosen because of its selective affinity for l-asparagine and because of its unusually high isoelectric point(8.6). a gene construction without the l-asparaginase native sign ... | 1995 | 18623425 |
| production of recombinant bacterial endoglucanase as a co-product with ethanol during fermentation using derivatives of escherichia coli ko11. | this study demonstrates a new approach to reduce the amount of fungal cellulase required for the conversion of cellulose into ethanol. escherichia coli ko11, a biocatalyst developed for the fermentation of hemicellulose syrups, was used to produce recombinant endoglucanase as a co-product with ethanol. seven different bacterial genes were expressed from plasmids in ko11. all produced cell-associated endoglucanase activity. ko11(ploi1620) containing erwinia chrysanthemi celz (egz) produced the hi ... | 1997 | 18636522 |
| phiec2, a new generalized transducing phage of erwinia chrysanthemi. | a collection of erwinia strains (chrysanthemi and carotovora) was screened for temperate phages. one of them, phiec2, turned out to be a generalized transducing phage. the structure of its dna was found to be 62 kb long, terminally redundant, and circularly permuted. the transducing properties of the phage are also briefly described. | 1984 | 18639822 |
| plant lesions promote the rapid multiplication of escherichia coli o157:h7 on postharvest lettuce. | several outbreaks of escherichia coli o157:h7 infections have been associated with minimally processed leafy vegetables in the united states. harvesting and processing cause plant tissue damage. in order to assess the role of plant tissue damage in the contamination of leafy greens with e. coli o157:h7, the effect of mechanical, physiological, and plant disease-induced lesions on the growth of this pathogen on postharvest romaine lettuce was investigated. within only 4 h after inoculation, the p ... | 2008 | 18641153 |
| global gene expression profiles suggest an important role for nutrient acquisition in early pathogenesis in a plant model of pseudomonas aeruginosa infection. | although pseudomonas aeruginosa is an opportunistic pathogen that does not often naturally infect alternate hosts, such as plants, the plant-p. aeruginosa model has become a widely recognized system for identifying new virulence determinants and studying the pathogenesis of the organism. here, we examine how both host factors and p. aeruginosa pao1 gene expression are affected in planta after infiltration into incompatible and compatible cultivars of tobacco (nicotiana tabacum l.). n. tabacum ha ... | 2008 | 18641163 |
| complete genome sequence of the n2-fixing broad host range endophyte klebsiella pneumoniae 342 and virulence predictions verified in mice. | we report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, klebsiella pneumoniae 342. although k. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world), while maintaining a mutualistic relationship that encompasses supplying organic nitrogen to the host plant. genomic ... | 2008 | 18654632 |
| roles for loop 2 residues of alpha1 glycine receptors in agonist activation. | the present study tested the hypothesis that several residues in loop 2 of alpha1 glycine receptors (glyrs) play important roles in mediating the transduction of agonist activation to channel gating. this was accomplished by investigating the effect of cysteine point mutations at positions 50-60 on glycine responses in alpha1glyrs using two-electrode voltage clamp of xenopus oocytes. cysteine substitutions produced position-specific changes in glycine sensitivity that were consistent with a beta ... | 2008 | 18658152 |
| spx mediates oxidative stress regulation of the methionine sulfoxide reductases operon in bacillus subtilis. | all aerobically grown living cells are exposed to oxidative damage by reactive oxygen species (ros). a major damage by ros to proteins is caused by covalent modifications of methionine residues giving methionine sulfoxide (met-so). methionine sulfoxide reductases are enzymes able to regenerate methionine and restore protein function after oxidative damage. | 2008 | 18662407 |
| characterization of chromosomal regions conserved in yersinia pseudotuberculosis and lost by yersinia pestis. | the transformation of the enteropathogenic bacterium yersinia pseudotuberculosis into the plague bacillus, yersinia pestis, has been accompanied by extensive genetic loss. this study focused on chromosomal regions conserved in y. pseudotuberculosis and lost during its transformation into y. pestis. an extensive pcr screening of 78 strains of the two species identified five regions (r1 to r5) and four open reading frames (orfs; orf1 to orf4) that were conserved in y. pseudotuberculosis and absent ... | 2008 | 18678673 |
| expression, purification and crystallization of helicobacter pylori l-asparaginase. | the l-asparaginases from escherichia coli and erwinia chrysanthemi are effective drugs that have been used in the treatment of acute childhood lymphoblastic leukaemia for over 30 years. however, despite their therapeutic potential, they can cause serious side effects as a consequence of their intrinsic glutaminase activity, which leads to l-glutamine depletion in the blood. consequently, new asparaginases with low glutaminase activity, fewer side effects and high activity towards l-asparagine ar ... | 2008 | 18678946 |
| crystallization and preliminary crystallographic analysis of mannosyl-3-phosphoglycerate synthase from rubrobacter xylanophilus. | rubrobacter xylanophilus is the only gram-positive bacterium known to synthesize the compatible solute mannosylglycerate (mg), which is commonly found in hyperthermophilic archaea and some thermophilic bacteria. unlike the salt-dependent pattern of accumulation observed in (hyper)thermophiles, in r. xylanophilus mg accumulates constitutively. the synthesis of mg in r. xylanophilus was tracked from gdp-mannose and 3-phosphoglycerate, but the genome sequence of the organism failed to reveal any of ... | 2008 | 18678952 |
| type iii secretion system genes of dickeya dadantii 3937 are induced by plant phenolic acids. | dickeya dadantii is a broad-host range phytopathogen. d. dadantii 3937 (ech3937) possesses a type iii secretion system (t3ss), a major virulence factor secretion system in many gram-negative pathogens of plants and animals. in ech3937, the t3ss is regulated by two major regulatory pathways, hrpx/hrpy-hrps-hrpl and gacs/gaca-rsmb-rsma pathways. although the plant apoplast environment, low ph, low temperature, and absence of complex nitrogen sources in media have been associated with the induction ... | 2008 | 18698421 |
| abscisic acid deficiency leads to rapid activation of tomato defence responses upon infection with erwinia chrysanthemi. | in addition to the important role of abscisic acid (aba) in abiotic stress signalling, basal and high aba levels appear to have a negative effect on disease resistance. using the aba-deficient sitiens tomato (solanum lycopersicum) mutant and different application methods of exogenous aba, we demonstrated the influence of this plant hormone on disease progression of erwinia chrysanthemi. this necrotrophic plant pathogenic bacterium is responsible for soft rot disease on many plant species, causin ... | 2008 | 18705880 |
| signal discrimination by differential regulation of protein stability in quorum sensing. | quorum sensing (qs) is a communication mechanism exploited by a large variety of bacteria to coordinate gene expression at the population level. in gram-negative bacteria, qs occurs via synthesis and detection of small chemical signals, most of which belong to the acyl-homoserine lactone class. in such a system, binding of an acyl-homoserine lactone signal to its cognate transcriptional regulator (r-protein) often induces stabilization and subsequent dimerization of the r-protein, which results ... | 2008 | 18721812 |
| identification of lacto-n-biose i phosphorylase from vibrio vulnificus cmcp6. | a beta-1,3-galactosyl-n-acetylhexosamine phosphorylase (galglynacp) homolog gene was cloned from vibrio vulnificus cmcp6. in synthetic reactions, the recombinant enzyme acted only with glcnac and galnac as acceptors in the presence of alpha-d-galactose-1-phosphate as a donor to form lacto-n-biose i (lnb) (galbeta1 --> 3glcnac) and galacto-n-biose (gnb) (galbeta1 --> 3galnac), respectively. glcnac was a much better acceptor than galnac. the enzyme also phosphorolysed lnb faster than it phosphorol ... | 2008 | 18723650 |
| characterization of tolc efflux pump proteins from pasteurella multocida. | two tolc homologs, pm0527 and pm1980, were identified for pasteurella multocida. a pm0527 mutant displayed increased susceptibility to a range of chemicals, including rifampin (512-fold) and acridine orange (128-fold). a pm1980 mutant showed increased susceptibility to rifampin, ceftazidime, and vancomycin. | 2008 | 18725450 |
| pecs is a global regulator of the symptomatic phase in the phytopathogenic bacterium erwinia chrysanthemi 3937. | pathogenicity of the enterobacterium erwinia chrysanthemi (dickeya dadantii), the causative agent of soft-rot disease in many plants, is a complex process involving several factors whose production is subject to temporal regulation during infection. pecs is a transcriptional regulator that controls production of various virulence factors. here, we used microarray analysis to define the pecs regulon and demonstrated that pecs notably regulates a wide range of genes that could be linked to pathoge ... | 2008 | 18790868 |
| iron(iii) uptake and release by chrysobactin, a siderophore of the phytophatogenic bacterium erwinia chrysanthemi. | the plant pathogenic enterobacterium erwinia chrysanthemi causes important soft-rot disease on a wide range of plants including vegetables and ornamentals of economic importance. it produces a major mono(catecholate) siderophore, chrysobactin (alpha-n-(2,3-dihydroxybenzoyl)-d-lysyl-l-serine). to unravel the role of chrysobactin in the virulence of e. chrysanthemi, its iron(iii) coordination properties were thus investigated in aqueous solutions using electrospray ionization mass spectrometric, p ... | 2008 | 18803373 |
| the missing link: bordetella petrii is endowed with both the metabolic versatility of environmental bacteria and virulence traits of pathogenic bordetellae. | bordetella petrii is the only environmental species hitherto found among the otherwise host-restricted and pathogenic members of the genus bordetella. phylogenetically, it connects the pathogenic bordetellae and environmental bacteria of the genera achromobacter and alcaligenes, which are opportunistic pathogens. b. petrii strains have been isolated from very different environmental niches, including river sediment, polluted soil, marine sponges and a grass root. recently, clinical isolates asso ... | 2008 | 18826580 |
| the flagellar sigma factor flia is required for dickeya dadantii virulence. | the genome sequence of the enterobacteriaceae phytopathogen dickeya dadantii (formerly erwinia chrysanthemi) revealed homologs of genes required for a complete flagellar secretion system and one flagellin gene. we found that d. dadantii was able to swim and swarm but that ability to swarm was dependent upon both growth media and temperature. mutation of the d. dadantii flia gene was pleiotropic, with the alternate sigma factor required for flagella production and development of disease symptoms ... | 2008 | 18842093 |
| analysis of the laci family regulators of erwinia chrysanthemi 3937, involvement in the bacterial phytopathogenicity. | analysis of the regulators of the laci family was performed in order to identify those potentially involved in pathogenicity of erwinia chrysanthemi (dickeya dadantii). among the 18 members of the laci family, the function of 11 members is either known or predicted and only 7 members have, as yet, no proposed function. inactivation of these seven genes, called lfar, lfbr, lfcr, lfdr, lfer, lffr, and lfgr, demonstrated that four of them are important for plant infection. the lfar and lfcr mutants ... | 2008 | 18842096 |
| in silico models for the human alpha4beta2 nicotinic acetylcholine receptor. | the neuronal alpha4beta2 nicotinic acetylcholine receptor (nachr) is one of the most widely expressed nachr subtypes in the brain. its subunits have high sequence identity (54 and 46% for alpha4 and beta2, respectively) with alpha and beta subunits in torpedo nachr. using the known structure of the torpedo nachr as a template, the closed-channel structure of the alpha4beta2 nachr was constructed through homology modeling. normal-mode analysis was performed on this closed structure and the result ... | 2008 | 18847252 |
| the impact of o(2) on the fe-s cluster biogenesis requirements of escherichia coli fnr. | in this study, the functions of two established fe-s cluster biogenesis pathways, isc (iron-sulfur cluster) and suf (sulfur mobilization), under aerobic and anaerobic growth conditions were compared by measuring the activity of the escherichia coli global anaerobic regulator fnr. a [4fe-4s] cluster is required for fnr activity under anaerobic conditions. an assay of the expression of fnr-dependent promoters in strains containing various deletions of the iscsuahscbafdx operon revealed that, under ... | 2008 | 18938178 |