Molecular Characterization of EMM-Like Genes in the MGA Regulon of Group A Streptococcus Strain ST4547

Sequence analysis of the 5' region of the emm gene was employed to differentiate 39 group A streptococci (GAS) isolates collected between 1989 to 1997 from patients and carriers in Kuala Lumpur. Sixty-one percent (24) of these isolates contained emm genes encoding the M protein for which M-antigen associations had not been made. The remaining strains bad emm sequences in agreement with previously recorded M-antigen associations. In some cases antigenic variations were observed among individual M types as well as the isolates tested compared to published M protein sequences. These differences were predominantly due to the non-synonymous base substitutions and occasionally, short insertions and deletions Nucleotide sequencing of the mga regulon of a new Malaysian emm type ST4547 group A streptococcus an opacity factor (OF) negative isolate, showed the existence of two emm-like genes, emm and mrp. The emm gene encoded the M protein whereas mrp gene encoded the IgG Fc receptor. The gene located upstream of the scpA gene, comprised 1305 nucleotides encoded a M protein of 435 amino acids in length with a predicted molecular weight of 49.0 kDa or a predicted mature protein of 394 amino acids with a molecular weight of 44. 7 kDa. At the upstream of this gene and downstream of mga gene another gene was found and designated as mrpST4547. The sequence of this gene comprised 1 167 nucleotides encoded a predicted protein of 388 amino acids in length with a predicted molecular weight of 42.2 kDa or a predicted mature protein of 347 amino acids with a molecular weight of 31.9 kDa. The mga regulon of the strain ST4547 had a mosaic structure consisting of DNA segments which were suggested to had originated from different OF positive and OF negative strains. The sequences flanking the hypervariable and C repeats of the emmST4547 gene showed high similarity to a corresponding region in the mga regulon of OF positive strains notably M15, M4, M22 and M50. In contrast, the sequence of the hypervariable and C repeats region of the emmST4547 gene revealed high similarity to equivalent regions in the OF negative strains. These data suggested that horizontal transfer of emm-like genes could occur between OF positive and OF negative strains resulting in divergence in the architecture of the mga regulon. This study showed that sequencing of the 5' region of the emm gene of GAS isolates was effective for surveying the sequence variability of the M protein and useful for monitoring GAS strain diversity in Malaysia as well as showing the mechanisms involved for antigenic diversity in M proteins. This study also il1ustrated a new mosaic in structure of mga regulon of OF negative strains with existence of mrp and emm genes. As far as this research was concerned to our knowledge, such a study has been done for the first time in a developing country

Identification of Phosphoprotien : Phosphoprotien and Phosphoprotien : Nucleocapsid Protein Interaction Domains of New Castle Disease Virus

Summary : The yeast two hybrid system has been used to identify domains of the Newcastle disease virus ( NDV ) phosphoprotien (P) involved in self –association and interaction with the nucleocapsid protein (NP). Deletion analysis was used to map the domain (s) of the P protein involved in P:P and P:NP interactions. The C- terminal 45 amino acids (residues 247-291) were shown to play a major role in both of interaction. Comparison of these finding with other report suggests that paramyxoviruses are different with respect to interaction domain(s) between these two essential viral proteins involved in genome replication

Hyper-Rational Choice and Economic Behaviour

In this paper, with help of the concept of hyper-rationality, we model the interaction between two investment companies by an important game as trickery game that has special equilibrium which called hyper-equilibrium. In trickery game, one company can choose cooperation with another company until the last moment and finally changes his action to non-cooperation which incur more loss to an opponent. Indeed, the hyper-equilibrium is the point in which only one player can displace equilibrium to another point by changing his action which causes profit or loss to other players so they cannot change their action. Our findings indicate that the kind of behaviour interactive, environmental conditions, and valuation system are based on hostility causes an equilibrium point to incur the maximum loss to an opponent

FIXED POINT OF MULTIVALUED CONTRACTIONS IN ORTHOGONAL MODULAR METRIC SPACES

In this paper we generalize the notion of O−set and establish some fixedpoint theorems for ⊥ − α − ψ−contraction multifunction in the setting of orthogonalmodular metric spaces. As consequences of these results we deduce some theorems inorthogonal modular metric spaces endowed with a graph and partial order. Finally,we establish some theorems for integral type contraction multifunctions and give someexamples to demonstrate the validity of the results

Purification and Characterization of Nipah Virus Nucleocapsid Protein Produced in Insect Cells

The nucleocapsid (N)protein of Nipah virus (NiV) is a major constituent of the viral proteins which play a role in encapsidation, regulating the transcription and replication of the viral genome. To investigate the use of a fusion system to aid the purification of the recombinant N protein for structural studies and potential use a diagnostic reagent, the NiV n gene was cloned into the pFastBacHT vector and and his tagged fusion protian was expressed in Sf9 insect cells by recombinant baculovirus. Western blot analysis of the recombinant fusion protein with anti-Niv antibodies produced a band of approximately 62 kDa. At time course study showed that the highest level of expression was achived after 3 days of incubation. Electron microscopic analysis of the NiV recombinant N fusion protein purified on a nickel- nitrilotriacetic asid resin column revealed different types of structures, including spherical, ring-like, particles. The light-scattering measurements of the recombinant N protein also confirmed the polydispersity of the sample with hydrodynamic radii of small and large types. The optical density spectra of the purified recombinant fusion protein reavealed a high A 260 / A 280 ratio, indicating the presence of nucleic acids. Western blotting and enzyme-linked immunosorbent assay result showed that the recombinant N protein exhibited the antigenic sites and conformation necessary for specific antigen-antibody recognition

Nipah virus glycoprotein: production in baculovirus and application in diagnosis

A method for serological diagnosis of Nipah virus (NiV) is described. DNA encoding truncated G protein of NiV was clone into the pFastbac HT vector, and the fusion protein to His-Tag was expressed in insect cells by recombinant baculovirus. The resulting His-G recombinant fusion protein was purified by affinity chromatography and used as the coating antigen for serological testing by in direct enzyme-linked immunosorbant assay (ELISA). When tested against a panel of swine serum samples, the recombinant G protein-based ELISA successfully discriminated all 40 samples previously determined to be serum neutralizing test (SNT) positive from 11 SNT negative samples. The data show that the recombinant G protein exhibit the antogenic epitopes and conformation necessary for specific antigen-antibody recognition. The main advantage of the recombinant G protein-base NiV ELISA compared to and ELISA using whole virus antigen is the use of single antigenic protein instead of inactivated whole virus which is required to be prepared under high risk and cost. This test is suitable for routine diagnosis of NiV and also for epidemiological surveys as it allows highly reliable testing of a large number of sera rapidly

Genome-wide estimation of firing efficiencies of origins of DNA replication from time-course copy number variation data

<p>Abstract</p> <p>Background</p> <p>DNA replication is a fundamental biological process during S phase of cell division. It is initiated from several hundreds of origins along whole chromosome with different firing efficiencies (or frequency of usage). Direct measurement of origin firing efficiency by techniques such as DNA combing are time-consuming and lack the ability to measure all origins. Recent genome-wide study of DNA replication approximated origin firing efficiency by indirectly measuring other quantities related to replication. However, these approximation methods do not reflect properties of origin firing and may lead to inappropriate estimations.</p> <p>Results</p> <p>In this paper, we develop a probabilistic model - Spanned Firing Time Model (SFTM) to characterize DNA replication process. The proposed model reflects current understandings about DNA replication. Origins in an individual cell may initiate replication randomly within a time window, but the population average exhibits a temporal program with some origins replicated early and the others late. By estimating DNA origin firing time and fork moving velocity from genome-wide time-course S-phase copy number variation data, we could estimate firing efficiency of all origins. The estimated firing efficiency is correlated well with the previous studies in fission and budding yeasts.</p> <p>Conclusions</p> <p>The new probabilistic model enables sensitive identification of origins as well as genome-wide estimation of origin firing efficiency. We have successfully estimated firing efficiencies of all origins in S.cerevisiae, S.pombe and human chromosomes 21 and 22.</p

Pregled nekih hemijskih jedinjenja i masnih kiselina u mesu gajenog šarana (cyprinus carpio) i belog amura (ctenopharyngodon idella)

This study was conducted to determine of some chemical compounds (proteins, lipids, moisture and ash) and fatty acids in cultured two species of common carp (Cyprinus carpio) and grass carp (Ctenopharyngodon idella). Results of this study showed that the amount of saturated fatty acids (SFA) in common carp and grass carp were 35.21 ± 2.19% and 27.18 ± 2.63%, respectively and saturated fatty acids (SFA) in common carp was higher compared to grass carp (p0.05). This study showed that PUFA was higher than SFA in Grass carp while SFA was higher than PUFA in common carp. There were significant differences in protein, lipid and moisture in two species (p0.05)

Adaptive expression responses in the Pol-γ null strain of S. pombe depleted of mitochondrial genome

<p>Abstract</p> <p>Background</p> <p>DNA polymerase γ(Pol-γ) has been shown to be essential for maintenance of the mitochondrial genome (mtDNA) in the petite-positive budding yeast <it>Saccharomyces cerevisiae</it>. Budding yeast cells lacking mitochondria exhibit a slow-growing or petite-colony phenotype. Petite strains fail to grow on non-fermentable carbon sources. However, it is not clear whether the Pol-γ is required for mtDNA maintenance in the petite-negative fission yeast <it>Schizosaccharomyces pombe</it>.</p> <p>Results</p> <p>We show that disruption of the nuclear gene <it>pog1</it>⁺that encodes Pol-γ is sufficient to deplete mtDNA in <it>S. pombe</it>. Cells bearing <it>pog1Δ </it>allele require substantial growth periods to form petite colonies. Mitotracker assays indicate that <it>pog1Δ </it>cells are defective in mitochondrial function and EM analyses suggest that <it>pog1Δ </it>cells lack normal mitochondrial structures. Depletion of mtDNA in <it>pog1Δ </it>cells is evident from quantitative real-time PCR assays. Genome-wide expression profiles of <it>pog1Δ </it>and other mtDNA-less cells reveal that many genes involved in response to stimulus, energy derivation by oxidation of organic compounds, cellular carbohydrate metabolism, and energy reserve metabolism are induced. Conversely, many genes encoding proteins involved in amino acid metabolism and oxidative phosphorylation are repressed.</p> <p>Conclusion</p> <p>By showing that Pol-γ is essential for mtDNA maintenance and disruption of <it>pog1</it>⁺alters the genome-wide expression profiles, we demonstrated that cells lacking mtDNA exhibit adaptive nuclear gene expression responses in the petite-negative <it>S. pombe</it>.</p