scholarly journals Penicillin resistance in the intestinal spirochaete Brachyspira pilosicoli associated with OXA-136 and OXA-137, two new variants of the class D β-lactamase OXA-63

2008 ◽  
Vol 57 (9) ◽  
pp. 1122-1128 ◽  
Author(s):  
Sheila M. Mortimer-Jones ◽  
Nyree D. Phillips ◽  
Tom La ◽  
Ram Naresh ◽  
David J. Hampson
Keyword(s):  
Amino Acid ◽  
Gc Content ◽  
Penicillin Resistance ◽  
Predicted Amino Acid Sequence ◽  
Gene Encoding ◽  
Brachyspira Pilosicoli ◽  
Class D ◽  
Genes Encoding ◽  
Pcr Products ◽  
Additional Amino Acid

Penicillin resistance mediated by β-lactamase activity has been reported previously in the anaerobic intestinal spirochaete Brachyspira pilosicoli, and a novel class D β-lactamase (OXA-63) hydrolysing oxacillin was described recently in a resistant human strain from France. In the current study, 18 B. pilosicoli strains from Australia and Papua New Guinea were tested for ampicillin and oxacillin susceptibility, and investigated for the presence of the class D β-lactamase gene bla OXA-63 using PCR. PCR products were amplified from seven human and four porcine strains that were penicillin resistant, but not from seven penicillin-sensitive strains. Sequence analysis of the whole gene amplified from seven of the resistant strains from humans and pigs revealed only minor nucleotide differences among them, but there were significant differences compared with bla OXA-63. The predicted amino acid sequence of the enzyme from all seven strains had the same key structural motifs as the previously reported OXA-63, but two variants with 94–95 % identity with OXA-63 were identified. OXA-136 had an additional amino acid and 12 other consistent amino acid substitutions compared with OXA-63. OXA-137 had the same differences compared with OXA-63 as OXA-136, but had an additional amino acid substitution at position 16. No structures consistent with integrons or transposons were found in the nucleotide sequences in the vicinity of bla OXA-136 in partially sequenced B. pilosicoli strain 95/1000, and the GC content (25.2 mol%) of the gene was similar to that of the whole genome. The gene encoding OXA-136 from B. pilosicoli strain Cof-10 conferred penicillin resistance on Escherichia coli. This study shows that penicillin resistance in human and porcine B. pilosicoli strains from Australia is associated with the production of two variants of OXA-63, and that susceptible strains lack the genes encoding OXA-63 or the variants.

Cloning and characterization of a gene encoding pig epidermal growth factor

1991 ◽  
Vol 6 (1) ◽  
pp. 63-70 ◽  
Author(s):  
J. C. Pascall ◽  
D. S. C. Jones ◽  
S. M. Doel ◽  
J. M. Clements ◽  
M. Hunter ◽  
...  
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Amino Acid Sequence ◽  
Egf Receptor ◽  
Predicted Amino Acid Sequence ◽  
Recombinant Polypeptide ◽  
Gene Encoding ◽  
Epidermal Growth ◽  
Direct Amplification

ABSTRACT A portion of the pig epidermal growth factor (EGF) gene has been isolated and characterized. The nucleotide sequencies of exons 20 and 21, which encode the EGF region of the precursor protein, show 85% similarity with the human EGF gene sequence. In addition, conservation of the intron—exon boundaries between the two species was generally observed. Although the pig exon 21 appeared to lack a single nucleotide at its 5′ end relative to the human gene, sequences obtained by direct amplification of the genomic DNA around the 5′ end of this exon using the polymerase chain reaction, and from a pig EGF cDNA recombinant isolated from a kidney library, indicated that the deletion was probably a cloning artifact. Comparison of the predicted amino acid sequence of pig EGF with that of EGF from other species, as well as with several other polypeptides which bind to the EGF receptor, indicated conservation of Gly18, Tyr37, Gly39 and Arg41 in addition to all six cysteine residues and Leu47, which are known to be critical for biological activity. A synthetic gene encoding the predicted amino acid sequence of pig EGF was expressed in yeast. The recombinant polypeptide was shown to compete with 125I-labelled mouse EGF for binding to cells and to stimulate DNA synthesis in quiescent monolayers of Swiss 3T3 cells.

scholarly journals Rho1p-Bni1p-Spa2p Interactions: Implication in Localization of Bni1p at the Bud Site and Regulation of the Actin Cytoskeleton inSaccharomyces cerevisiae

1998 ◽  
Vol 9 (5) ◽  
pp. 1221-1233 ◽  
Author(s):  
Takeshi Fujiwara ◽  
Kazuma Tanaka ◽  
Akihisa Mino ◽  
Mitsuhiro Kikyo ◽  
Kazuo Takahashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Actin Cytoskeleton ◽  
Binding Protein ◽  
Microscopic Analysis ◽  
Mitogen Activated Protein Kinase ◽  
Gene Encoding ◽  
Amino Acid Region ◽  
Genes Encoding ◽  
Mitogen Activated Protein ◽  
Acid Region

Rho1p is a yeast homolog of mammalian RhoA small GTP-binding protein. Rho1p is localized at the growth sites and required for bud formation. We have recently shown that Bni1p is a potential target of Rho1p and that Bni1p regulates reorganization of the actin cytoskeleton through interactions with profilin, an actin monomer-binding protein. Using the yeast two-hybrid screening system, we cloned a gene encoding a protein that interacted with Bni1p. This protein, Spa2p, was known to be localized at the bud tip and to be implicated in the establishment of cell polarity. The C-terminal 254 amino acid region of Spa2p, Spa2p(1213–1466), directly bound to a 162-amino acid region of Bni1p, Bni1p(826–987). Genetic analyses revealed that both thebni1 and spa2 mutations showed synthetic lethal interactions with mutations in the genes encoding components of the Pkc1p-mitogen-activated protein kinase pathway, in which Pkc1p is another target of Rho1p. Immunofluorescence microscopic analysis showed that Bni1p was localized at the bud tip in wild-type cells. However, in the spa2 mutant, Bni1p was not localized at the bud tip and instead localized diffusely in the cytoplasm. A mutant Bni1p, which lacked the Rho1p-binding region, also failed to be localized at the bud tip. These results indicate that both Rho1p and Spa2p are involved in the localization of Bni1p at the growth sites where Rho1p regulates reorganization of the actin cytoskeleton through Bni1p.

scholarly journals Sulfonamide Resistance in Streptococcus pyogenes Is Associated with Differences in the Amino Acid Sequence of Its Chromosomal Dihydropteroate Synthase

1998 ◽  
Vol 42 (5) ◽  
pp. 1062-1067 ◽  
Author(s):  
Göte Swedberg ◽  
Signe Ringertz ◽  
Ola Sköld
Keyword(s):  
Amino Acid ◽  
Streptococcus Pyogenes ◽  
Gtp Cyclohydrolase ◽  
Gene Encoding ◽  
Additional Indication ◽  
Kinetic Measurements ◽  
Dihydropteroate Synthase ◽  
Development Of Resistance ◽  
Sulfonamide Resistance ◽  
Genes Encoding

ABSTRACT Sulfonamide resistance in recent isolates of Streptococcus pyogenes was found to be associated with alterations of the chromosomally encoded dihydropteroate synthase (DHPS). There were 111 different nucleotides (13.8%) in the genes found in susceptible and resistant isolates, respectively, resulting in 30 amino acid changes (11.3%). These substantial changes suggested the possibility of a foreign origin of the resistance gene, in parallel to what has already been found for sulfonamide resistance in Neisseria meningitidis. The gene encoding DHPS was linked to at least three other genes encoding enzymes of the folate pathway. These genes were in the order GTP cyclohydrolase, dihydropteroate synthase, dihydroneopterin aldolase, and hydroxymethyldihydropterin pyrophosphokinase. The nucleotide differences in genes from resistant and susceptible strains extended from the beginning of the GTP cyclohydrolase gene to the end of the gene encoding DHPS, an additional indication for gene transfer in the development of resistance. Kinetic measurements established different affinities for sulfathiazole for DHPS enzymes isolated from resistant and susceptible strains.

scholarly journals Molecular and Immunological Analyses of the Mycobacterium avium Homolog of the Immunodominant Mycobacterium leprae 35-Kilodalton Protein

1998 ◽  
Vol 66 (6) ◽  
pp. 2684-2690 ◽  
Author(s):  
James A. Triccas ◽  
Nathalie Winter ◽  
Paul W. Roche ◽  
Andrea Gilpin ◽  
Kathleen E. Kendrick ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mycobacterium Avium ◽  
Amino Acid Level ◽  
Streptomyces Griseus ◽  
Amino Acid Identity ◽  
Delayed Type Hypersensitivity ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Species Specific ◽  
35 Kda Protein

ABSTRACT The analysis of host immunity to mycobacteria and the development of discriminatory diagnostic reagents relies on the characterization of conserved and species-specific mycobacterial antigens. In this report, we have characterized the Mycobacterium avium homolog of the highly immunogenic M. leprae 35-kDa protein. The genes encoding these two proteins were well conserved, having 82% DNA identity and 90% identity at the amino acid level. Moreover both proteins, purified from the fast-growing host M. smegmatis, formed multimeric complexes of around 1000 kDa in size and were antigenically related as assessed through their recognition by antibodies and T cells from M. leprae-infected individuals. The 35-kDa protein exhibited significant sequence identity with proteins from Streptomyces griseus and the cyanobacterium Synechoccocus sp. strain PCC 7942 that are up-regulated under conditions of nutrient deprivation. The 67% amino acid identity between the M. avium 35-kDa protein and SrpI of Synechoccocus was spread across the sequences of both proteins, while the homologous regions of the 35-kDa protein and the P3 sporulation protein of S. griseus were interrupted in the P3 protein by a divergent central region. Assessment by PCR demonstrated that the gene encoding the M. avium35-kDa protein was present in all 30 M. avium clinical isolates tested but absent from M. intracellulare,M. tuberculosis, or M. bovis BCG. Mice infected with M. avium, but not M. bovis BCG, developed specific immunoglobulin G antibodies to the 35-kDa protein, consistent with the observation that tuberculosis patients do not recognize the antigen. Strong delayed-type hypersensitivity was elicited by the protein in guinea pigs sensitized with M. avium.

scholarly journals Noncatalytic Docking Domains of Cellulosomes of Anaerobic Fungi

2001 ◽  
Vol 183 (18) ◽  
pp. 5325-5333 ◽  
Author(s):  
Peter J. M. Steenbakkers ◽  
Xin-Liang Li ◽  
Eduardo A. Ximenes ◽  
Jorik G. Arts ◽  
Huizhong Chen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cdna Library ◽  
Genomic Dna ◽  
Catalytic Domain ◽  
Sequence Information ◽  
Anaerobic Fungi ◽  
Degenerate Primers ◽  
New Genes ◽  
Genes Encoding ◽  
Pcr Products

ABSTRACT A method is presented for the specific isolation of genes encoding cellulosome components from anaerobic fungi. The catalytic components of the cellulosome of anaerobic fungi typically contain, besides the catalytic domain, mostly two copies of a 40-amino-acid cysteine-rich, noncatalytic docking domain (NCDD) interspaced by short linkers. Degenerate primers were designed to anneal to the highly conserved region within the NCDDs of the monocentric fungusPiromyces sp. strain E2 and the polycentric fungusOrpinomyces sp. strain PC-2. Through PCR using cDNA fromOrpinomyces sp. and genomic DNA fromPiromyces sp. as templates, respectively, 9 and 19 PCR products were isolated encoding novel NCDD linker sequences. Screening of an Orpinomyces sp. cDNA library with four of these PCR products resulted in the isolation of new genes encoding cellulosome components. An alignment of the partial NCDD sequence information obtained and an alignment of database-accessible NCDD sequences, focusing on the number and position of cysteine residues, indicated the presence of three structural subfamilies within fungal NCDDs. Furthermore, evidence is presented that the NCDDs in CelC from the polycentric fungus Orpinomyces sp. strain PC-2 specifically recognize four proteins in a cellulosome preparation, indicating the presence of multiple scaffoldins.

scholarly journals Expression of a gene encoding a novel ferredoxin in the cyanobacterium Synechococcus 6301

1988 ◽  
Vol 252 (2) ◽  
pp. 563-569 ◽  
Author(s):  
A L Cozens ◽  
J E Walker
Keyword(s):  
Amino Acid ◽  
Protein Sequence ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Transcriptional Initiation ◽  
Genes Encoding ◽  
Synechococcus 6301 ◽  
Methionine Codon ◽  
A Site

A gene was discovered in the cyanobacterium Synechococcus 6301 that encodes a protein highly related to members of the [2Fe-2S] ferredoxin family found in chloroplasts and cyanobacteria. It follows a cluster of seven genes encoding subunits of the cyanobacterial ATP synthase complex. It is transcribed as a monocistronic mRNA of 408 nucleotide residues. Transcription starts at a site 55 bp upstream of the initiator methionine codon. Transcriptional initiation and termination signals with sequences similar to those found in Escherichia coli are not present. Comparison of the predicted sequence of the ferredoxin protein with those of other cyanobacterial and plant ferredoxins shows an average sequences identity of about 40%. Twelve amino acid residues are invariant, including the four cysteine residues that provide ligands for the [2Fe-2S] cluster. The deduced Synechococcus ferredoxin protein sequence has a C-terminal extension of eight amino acid residues relative to most other 2Fe-2S ferredoxins except for those from halobacteria, which also have a C-terminal extension. The sequence of the Synechococcus protein is most closely related to ferredoxins from the two complex cyanobacteria Chlorogloeopsis fritschii and Mastigocladus laminosus. The deduced protein sequence is not that of the major soluble ferredoxin that has been isolated from Synechococcus 6301 and is reported in the accompanying paper [Wada, Masui, Matsubara & Rogers (1988) Biochem. J. 252, 571-575]. So it appears to be a novel [2Fe-2S] ferredoxin and Synechococcus 6301 contains at least two [2Fe-2S] ferredoxins, which may have different roles in vivo.

scholarly journals Construction of Deoxyriboaldolase-Overexpressing Escherichia coli and Its Application to 2-Deoxyribose 5-Phosphate Synthesis from Glucose and Acetaldehyde for 2′-Deoxyribonucleoside Production

2003 ◽  
Vol 69 (7) ◽  
pp. 3791-3797 ◽  
Author(s):  
Nobuyuki Horinouchi ◽  
Jun Ogawa ◽  
Takafumi Sakai ◽  
Takako Kawano ◽  
Seiichiro Matsumoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Specific Activity ◽  
Cell Extract ◽  
Predicted Amino Acid Sequence ◽  
Enzymatic Reactions ◽  
Chromosomal Dna ◽  
Gene Encoding ◽  
Reading Frame ◽  
E Coli

ABSTRACT The gene encoding a deoxyriboaldolase (DERA) was cloned from the chromosomal DNA of Klebsiella pneumoniae B-4-4. This gene contains an open reading frame consisting of 780 nucleotides encoding 259 amino acid residues. The predicted amino acid sequence exhibited 94.6% homology with the sequence of DERA from Escherichia coli. The DERA of K. pneumoniae was expressed in recombinant E. coli cells, and the specific activity of the enzyme in the cell extract was as high as 2.5 U/mg, which was threefold higher than the specific activity in the K. pneumoniae cell extract. One of the E. coli transformants, 10B5/pTS8, which had a defect in alkaline phosphatase activity, was a good catalyst for 2-deoxyribose 5-phosphate (DR5P) synthesis from glyceraldehyde 3-phosphate and acetaldehyde. The E. coli cells produced DR5P from glucose and acetaldehyde in the presence of ATP. Under the optimal conditions, 100 mM DR5P was produced from 900 mM glucose, 200 mM acetaldehyde, and 100 mM ATP by the E. coli cells. The DR5P produced was further transformed to 2′-deoxyribonucleoside through coupling the enzymatic reactions of phosphopentomutase and nucleoside phosphorylase. These results indicated that production of 2′-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase is possible with the addition of a suitable energy source, such as ATP.

scholarly journals Genetic and Biochemical Characterization of FUS-1 (OXA-85), a Narrow-Spectrum Class D β-Lactamase from Fusobacterium nucleatum subsp. polymorphum

2006 ◽  
Vol 50 (8) ◽  
pp. 2673-2679 ◽  
Author(s):  
Christine Voha ◽  
Jean-Denis Docquier ◽  
Gian Maria Rossolini ◽  
Thierry Fosse
Keyword(s):  
Biochemical Characterization ◽  
Fusobacterium Nucleatum ◽  
Cloning And Sequencing ◽  
Gene Encoding ◽  
Brachyspira Pilosicoli ◽  
Reading Frame ◽  
New Class ◽  
Class D ◽  
Lactamase Gene

ABSTRACT Previous studies have reported β-lactamase-mediated penicillin resistance in Fusobacterium nucleatum, but no β-lactamase gene has yet been identified in this species. An F. nucleatum subsp. polymorphum strain resistant to penicillin and amoxicillin was isolated from a human periodontitis sample. DNA cloning and sequencing revealed a 765-bp open reading frame encoding a new class D β-lactamase named FUS-1 (OXA-85). A recombinant Escherichia coli strain carrying the bla FUS-1 gene exhibited resistance to amoxicillin with a moderate decrease in the MICs with clavulanic acid. The bla FUS-1 gene was found in two additional clonally unrelated F. nucleatum subsp. polymorphum isolates. It was located on the chromosome in a peculiar genetic environment where a gene encoding a putative transposase-like protein is found, suggesting a possible acquisition of this class D β-lactamase gene. The FUS-1 enzyme showed the closest ancestral relationship with OXA-63 from Brachyspira pilosicoli (53% identity) and with putative chromosomal β-lactamases of Campylobacter spp. (40 to 42% identity). FUS-1 presents all of the conserved structural motifs of class D β-lactamases. Kinetic analysis revealed that FUS-1 exhibits a narrow substrate profile, efficiently hydrolyzing benzylpenicillin and oxacillin. FUS-1 was poorly inactivated by clavulanate and NaCl. FUS-1 is the first example of a class D β-lactamase produced by a gram-negative, anaerobic, rod-shaped bacterium to be characterized.

Characterization of a cDNA encoding a novel avian hypothalamic neuropeptide exerting an inhibitory effect on gonadotropin release

2001 ◽  
Vol 354 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Honoo SATAKE ◽  
Miki HISADA ◽  
Tsuyoshi KAWADA ◽  
Hiroyuki MINAKATA ◽  
Kazuyoshi UKENA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Basic Amino Acid ◽  
Inhibitory Effect ◽  
Gene Encoding ◽  
Specific Expression ◽  
Gonadotropin Secretion ◽  
Putative Gene ◽  
Gonadotropin Release ◽  
Pcr Products ◽  
Gonadotropin Inhibitory Hormone

We previously isolated a novel dodecapeptide containing a C-terminal -Arg-Phe-NH2 sequence, SIKPSAYLPLRF-NH2 (RFamide peptide), from the quail brain. This quail RFamide peptide was shown to decrease gonadotropin release from the cultured anterior pituitary and to be located at least in the quail hypothalamo-hypophysial system. We therefore designated this RFamide peptide gonadotropin inhibitory hormone (GnIH). In the present study we characterized the GnIH cDNA from the quail brain by a combination of 3′ and 5′ rapid amplification of cDNA ends (‘RACE’). The deduced GnIH precursor consisted of 173 amino acid residues, encoding one GnIH and two putative gene-related peptide (GnIH-RP-1 and GnIH-RP-2) sequences that included -LPXRF (X = L or Q) at their C-termini. All these peptide sequences were flanked by a glycine C-terminal amidation signal and a single basic amino acid on each end as an endoproteolytic site. Southern blotting analysis of reverse-transcriptase-mediated PCR products demonstrated a specific expression of the gene encoding GnIH in the diencephalon including the hypothalamus. Furthermore, mass spectrometric analyses detected the mass numbers for matured GnIH and GnIH-RP-2, revealing that both peptides are produced from the precursor in the diencephalon as an endogenous ligand. Taken together, these results lead to the conclusion that GnIH is a hypothalamic factor responsible for the negative regulation of gonadotropin secretion. Furthermore, the presence of a novel RFamide peptide family containing a C-terminal -LPXRF-NH2 sequence has been revealed.

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