Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An immunogenic loop within the diphtheria toxin has been deleted from the B-subunit by a modification of the inverse polymerase chain reaction (IPCR) and replaced by a unique restriction endonuclease site. An oligonucleotide encoding an identified epitope sequence from the major outer membrane protein of Neisseria meningitidis of similar size and structure to that deleted has been introduced into the restriction site. Expression of the resulting chimeric B-subunit from Escherichia coli yielded a protein that was recognised by a panel of antibodies specific for the meningococcal epitope. Initial immunisation data suggest that this protein could elicit an antibody response against both diphtheria toxin and meningococcal proteins.
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PMID:Construction of an epitope vector utilising the diphtheria toxin B-subunit. 899 11

Current methods used to classify Chlamydia strains, including biological, morphological, and DNA hybridization techniques and major outer membrane protein (omp1) gene analysis, can be imprecise or difficult to perform. To facilitate classification, 2.8-kb partial ribosomal DNA (rDNA) segments from a Chlamydia trachomatis strain and a Chlamydia psittaci strain were amplified by PCR and sequenced. Subsequently, a 1,320-bp region in this segment, including both the 16S/23S intergenic spacer (232 +/- 11 bp) and domain I (620 +/- 2 bp) of the 23S gene, was sequenced from 41 additional strains and from the chlamydia-like organisms Simkania sp. strains "Z" and "Z1." When both parsimony and distance analyses were performed, these sequences were found to have variable regions that grouped the isolates into two lineages (C. trachomatis and non-C. trachomatis) and nine distinct genotypic groups. The C. trachomatis lineage included human, swine, and mousehamster groups. The non-C. trachomatis lineage included Chlamydia pecorum, Chlamydia pneumoniae, and C. psittaci abortion, avian, feline, and guinea pig groups. These nine groups were essentially equidistant from the genetic root and were congruent with groups identified previously by using DNA-DNA homology, genomic restriction endonuclease analysis, host specificity, tissue specificity, and/or disease production. Phylogenetic trees based on the intergenic spacer or on domain I were congruent with trees previously derived from ompI sequences. DNA sequence analysis of either the intergenic spacer or domain I provides a rapid and reproducible method for identifying, grouping, and classifying chlamydial strains.
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PMID:The ribosomal intergenic spacer and domain I of the 23S rRNA gene are phylogenetic markers for Chlamydia spp. 910 37

The major outer-membrane protein. FomA, of Fusobacterium nucleatum has been associated with porin activity, interbacterial adherence and stimulation of host immune cells. Until now, molecular analysis of FomA has not been possible because previous attempts to clone the fomA gene were not successful. The inability to clone F. nucleatum genes led to speculation that Escherichia coli may not be a suitable host. This report concerns the amplification of the fomA gene of F. nucleatum T18 using oligonucleotide primers containing restriction endonuclease sites that allow cloning of fomA into the E. coli expression vector pMMB67. The resultant plasmid, pXWI, was transformed into E. coli DH5 alpha, providing high-level expression of recombinant FomA (rFomA). Amino acid sequencing of rFomA demonstrated that the FomA signal peptide was correctly processed by E. coli signal peptidase I. rFomA was correctly localized to the outer membrane by the E. coli export pathway. The rFomA protein also displayed the heat-modifiable oligomeric and conformational properties of native FomA (nFomA). This demonstration of rFomA expression, processing, export, and secondary and tertiary structure in E. coli provides support for the feasibility of molecular analysis of the structure and function of FomA and other F. nucleatum proteins using recombinant techniques.
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PMID:Cloning and expression of FomA, the major outer-membrane protein gene from Fusobacterium nucleatum T18. 913 12

Five Chlamydia psittaci isolates (1 turkey, 1 psittacine, 1 human, and 2 pigeon isolates) failed to react with serovar-specific monoclonal antibodies to known avian and mammalian C. psittaci serovars and were presumed to represent 1 or more new serovars. The isolates were characterized using restriction endonuclease analysis of the whole genome, polymerase chain reaction-restriction fragment length polymorphism of the major outer membrane protein genome, monoclonal antibody comparisons, and growth in tissue culture. Monoclonal antibodies were produced to the human isolate (MP) and to the psittacine isolate (VS225). The monoclonal antibody results show that the isolates represent 2 new avian serovars (serovars E and F). The restriction fragment length polymorphism analysis of the major outer membrane protein genome demonstrated that the isolates are distinct. The whole genome restriction endonuclease analysis data and the growth patterns in tissue culture indicate that the new serovars are similar to avian serovars recognized previously. A subspecies monoclonal antibody that reacted with serovars A and B also reacted with serovar E, indicating that these serovars are closely related. The results show that these isolates represent 2 new avian serovars, making them the fifth and sixth avian serovars identified in North American birds.
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PMID:Two new serovars of Chlamydia psittaci from North American birds. 921 Dec 35

To differentiate Chlamydia spp., a primer pair designed to generate a genus-specific region of the major outer membrane protein (MOMP) gene was used in a PCR to amplify a single DNA fragment of 245-259 bp. In the PCR, the expected single DNA fragment was amplified from strains of Chlamydia trachomatis, C. psittaci, C. pneumoniae and C. pecorum, respectively. By restriction endonuclease analysis with AluI and PvuII, the amplified products exhibited four distinct patterns, corresponding to the four species. It is, therefore, concluded that one-step PCR followed by restriction endonuclease analysis as described in this study could be a valuable method for the detection and differentiation of Chlamydia species.
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PMID:Differentiation of Chlamydia species by combined use of polymerase chain reaction and restriction endonuclease analysis. 965 75

We have determined the nucleotide sequence of the gene for a major outer membrane protein (MOMP) of apparent molecular weight 29.5 kD of the virulent Breinl strain of Rickettsia prowazekii. The gene contains an open reading frame (ORF) that encodes a 282-amino-acid polypeptide with a calculated molecular mass of 31549 daltons. A signal-like peptide sequence is found at the deduced N terminus. A heterologous 29.5-kD antigen expressed in Escherichia coli was shown to be secreted into the periplasm. A database search for similar protein sequences revealed considerable homology of the polypeptide with the E. coli peptidyl-prolyl cis/trans isomerase and related proteins of the parvulin family. The genes for MOMP of the virulent Breinl and EVir strains and the vaccine Madrid E strain were amplified using specific primers and cloned into expression vector pQE-30. We found that the polypeptides encoded by the recombinant DNAs do not differ in SDS-PAGE mobility, while the native MOMP of the Breinl strain is known to be different from the corresponding proteins of the Madrid E and EVir strains. Furthermore, no differences within the ORF for the 29.5-kD proteins of the three strains were found by restriction endonuclease analysis of polymerase chain reaction (PCR) products. A possible role of parvulin-like protein (Plp) in the virulence of epidemic typhus agent and the nature of interstrain differences are discussed. Near the plp gene on the opposite strand, an origin of the gene that codes for the SecA subunit of a preprotein translocase was found.
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PMID:Nucleotide sequence of the gene and features of the major outer membrane protein of a virulent Rickettsia prowazekii strain. 1038 9

Nine pathogenic strains of Rickettsia japonica isolated from patients with Oriental spotted fever were compared phenotypically and genotypically. Constitution and antigenicity of the proteins demonstrated to be the same among strains. Polymerase chain reaction (PCR) amplification of the two major outer membrane protein genes (ompA and ompB) and an intracellular spotted fever group-common antigen protein gene (rps120) produced the same sizes of products for all strains. Restriction fragment length polymorphism of the PCR products showed the same pattern among strains with each endonuclease. Thus, these strains belong to a single type, the same as the type strain YH (=ATCC VR-1363).
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PMID:Phenotypic and genotypic homogeneity of the strains of Rickettsia japonica isolated from patients with Oriental spotted fever. 1052 14

Kell, a 93 kDa type II membrane glycoprotein, and XK, a 444 amino acid multi-pass membrane protein, are blood group proteins that exist as a disulfide-bonded complex on human red cells. The mechanism of Kell/XK assembly was studied in transfected COS cells co-expressing Kell and XK proteins. Time course studies combined with endonuclease-H treatment and cell fractionation showed that Kell and XK are assembled in the endoplasmic reticulum. At later times the Kell component of the complex was not cleaved by endonuclease-H, indicating N-linked oligosaccharide processing and transport of the complex to a Golgi and/or a post-Golgi cell fraction. Surface-labeling of transfected COS cells, expressing both Kell and XK, demonstrated that the Kell/XK complex travels to the plasma membrane. XK expressed in the absence of Kell was also transported to the cell surface indicating that linkage of Kell and XK is not obligatory for cell surface expression.
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PMID:Intracellular assembly of Kell and XK blood group proteins. 1055 84

Directed mutagenesis of a gene coding for a membrane protein of the periodontopathogen Actinobacillus actinomycetemcomitans was achieved by conjugation. The gene was disrupted by insertion of an antibiotic cassette into a unique endonuclease restriction sequence engineered by inverse PCR. The disrupted gene was cloned into a conjugative plasmid and transferred from Escherichia coli to A. actinomycetemcomitans. The allelic replacement mutation resulted in the loss of a 22-kDa inner membrane protein. The loss of this protein (ImpA) resulted in changes in the outer membrane protein composition of the bacterium. Concurrent with the mutation in impA was a change in the pattern of growth of the mutant bacteria in broth cultures. The progenitor bacteria grew as a homogeneous suspension of cells compared to a granular, autoaggregating adherent cell population described for the mutant bacteria. These data suggest that ImpA may play a regulatory role or be directly involved in protein(s) that are exported and associated with colony variations in A. actinomycetemcomitans.
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PMID:impA, a gene coding for an inner membrane protein, influences colonial morphology of Actinobacillus actinomycetemcomitans. 1108 68

Intracellular free calcium ([Ca(2+)](i)) concentration, free oxygen radical (FOR) production, DNA breakdown, and plasma membrane phosphorylation were studied in human neutrophils activated with thapsigargin and phorbol myrisate acetate (PMA). Thapsigargin produced a rapid and sustained rise of [Ca(2+)](i), activated the endonuclease, and caused the breakdown of the neutrophil's DNA with a half-time close to 6 h. The protein kinase C activator PMA failed to inhibit the initial rise of [Ca(2+)](i), but inhibited the second phase of thapsigargin-induced calcium transient and completely blocked the activation of the endonuclease induced by thapsigargin. Thapsigargin induced a minor and delayed production of FOR, whereas PMA caused an abrupt and sustained FOR production that was enhanced by thapsigargin. Two plasma membrane proteins close to 50 and 64 kD were phosphorylated in PMA-activated neutrophils. These results suggest that the nonphosphorylated form of the membrane protein permits basal and thapsigargin-induced calcium entry. Phosphorylation by PMA of plasma membrane protein inhibits calcium uptake in both resting and thapsigargin-activated neutrophils and contributes to the block of the activation of the apoptotic endonuclease.
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PMID:Thapsigargin-induced calcium entry and apoptotic death of neutrophils are blocked by activation of protein kinase C. 1159 26


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