Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The syrA and syrB genes involved in syringomycin production in Pseudomonas syringae pv. syringae B301D were identified from an EcoRI-pLAFR3 cosmid library and then physically and functionally analyzed in relation to plant pathogenicity. Homologous recombination of the genes required for syringomycin production from cosmids pGX183 (syrA) and pGX56 (syrB), respectively, introduced into nontoxigenic (Tox-) Tn5 mutants W4S2545 and W4S770 resulted in the concomitant restoration of toxin production and full virulence. The disease indices of the Tox+ strains obtained by recombination of the cloned, homologous DNA into the corresponding Tn5 mutant were essentially equivalent to that of strain B301D-R and significantly higher than those of W4S2545 and W4S770. A 12-kilobase (kb) EcoRI fragment from pGX183 was subcloned (i.e., pGX15) and found to contain the sequences necessary for syringomycin production. A map of pGX15 prepared by a combination of restriction endonuclease digestions and Tn5 mutagenesis showed that the syrA sequence was 2.3 to 2.8 kb. Marker exchange of syrA::Tn5 from pGX15 into B301D-R yielded nonpathogenic phenotypes, indicating that syrA is a regulatory gene since it is necessary for both syringomycin production and pathogenicity. The 4.9-kb EcoRI fragment from pGX56 was subcloned (i.e., pGX4) and shown to carry the syrB sequence which was 2.4 to 3.3 kb. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of protein extracts from B301D-R associated five proteins, ranging from approximately 130,000 to approximately 470,000 in molecular weight, with syringomycin production. The syrA and syrB genes were required for the formation of proteins SR4 (approximately 350,000) and SR5 (approximately 130,000), which are believed to be components of the syringomycin synthetase complex.
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PMID:Physical and functional analyses of the syrA and syrB genes involved in syringomycin production by Pseudomonas syringae pv. syringae. 284 10

Spirochetes were isolated from 71 subadult Ixodes dentatus removed from cottontail rabbits captured in Millbrook, N.Y., and in New York, N.Y. Spirochetes were also cultured from kidney tissues of six rabbits. While all isolates reacted with monoclonal antibody H9724, which identifies the spirochetes as borreliae, more than half did not bind with antibody H5332 and even fewer reacted with H3TS, both of which were produced to outer surface protein A of Borrelia burgdorferi. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profiles of three isolates differed from one another and from all previously characterized B. burgdorferi strains from humans, ticks, and wildlife in North America. The 12 periplasmic flagella that originated subterminally from each pointed end of a rabbit Borellia isolate contrasted with the 11 or fewer flagella for B. burgdorferi reported previously from North America. Although DNA homology and restriction endonuclease analysis also revealed differences among a rabbit kidney isolate, an I. dentatus isolate, and B. burgdorferi B31, similarities were sufficient to lead us to conclude that the borreliae in rabbits and I. dentatus are B. burgdorferi. Enzyme-linked immunosorbent assay titers of sera from humans with diagnosed Lyme disease to rabbit tick B. burgdorferi were often similar to one another and to those recorded for a reference B. burgdorferi strain.
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PMID:Antigenically variable Borrelia burgdorferi isolated from cottontail rabbits and Ixodes dentatus in rural and urban areas. 291 24

We report that centrifugation at relatively high g-forces reduces the ability of competent cells of Bacillus subtilis to bind and take up DNA, and to be transformed. The centrifugation supernatant from competent cells restores this reduction of competence; the supernatant from non-competent cells is inactive. Phosphocellulose chromatography of centrifugation supernatants from radioactive competent cultures gave rise to six sharp peaks, together, these were shown by subsequent SDS polyacrylamide gel electrophoresis to contain over 60 different polypeptide bands. Peak II, which showed competence restoring activity, produced three polypeptides. When these bands were further examined, one of these exhibited DNA binding activity and the other two each contained a different endonuclease. Competence restoring activity was not recovered from the SDS polyacrylamide gel of peak II. The three peaks from non-competent cultures produced altogether five faint bands in gel electrophoresis. None of these bands were similar to those found in peak II.
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PMID:Competence related proteins in the supernatant of competent cells of Bacillus subtilis. 298 22

Eleven European isolates of bovine herpesvirus 1 (BHV-1), together with two reference virus strains were compared by restriction endonuclease digestion, by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), and by their reactivity with a panel of monoclonal antibodies (McAb's). Based on the cleavage pattern of viral DNA with the restriction endonuclease Hind III the strains could be assigned to one of two established major virus types. Analysis by SDS-PAGE of viral polypeptides revealed that four protein species either displayed virus type or subtype specific minor variation of migration characteristics. Of 43 McAb's tested all reacted with all type 1 strains, whereas five antibodies failed to recognize some of the type 2 viruses. The existence of type specific variations among virus specified proteins was further evidenced by the recovery of one McAb recognizing type 1 viruses only. The data show that BHV-1 isolates can be assigned to established virus types according to the SDS-PAGE profile of viral proteins or the selective reactivity with type specific McAb's.
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PMID:European isolates of bovine herpesvirus 1: a comparison of restriction endonuclease sites, polypeptides, and reactivity with monoclonal antibodies. 299 Mar 89

This report presents data showing that several virus isolates recovered in Argentina, mainly from calves with non-purulent meningo-encephalitis, represent a hitherto unrecognized antigenic variant of BHV-1. The following experimental approaches have been adopted to demonstrate both the unique features among and the relatedness with BHV-1 of these isolates: i) crossed serum neutralization test with rabbit immune sera, ii) analysis by SDS-polyacrylamide gel electrophoresis of radio-labeled virus induced polypeptides and glycoproteins, iii) discriminating reactivity of a panel of monoclonal antibodies which recognize known virus types, and iv) restriction endonuclease analysis of viral DNA. Another strain of BHV-1, which exhibits a specific neuropathogenic potential [Hall et al., Austral. Vet. J. 42, 229-237 (1966)] shares all major features with the viral strains originating from Argentina. Our results imply that antigenic variants of BHV-1 exist and that they can be accurately and easily identified and differentiated by the available methods.
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PMID:Bovine herpesvirus 1: molecular and antigenic characteristics of variant viruses isolated from calves with neurological disease. 300 86

Sixteen isolates of Mycoplasma ovipneumoniae recovered from the nasal tract or lungs of sheep from different flocks in New Zealand were examined by bacterial restriction endonuclease DNA analysis (BRENDA) using EcoR1 and by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). All isolates gave BRENDA patterns which differed entirely from one another. Following 20 serial passages (corresponding to approximately 67 generations) of an isolate, no change was detected in the BRENDA pattern. When eight isolates were examined by SDS-PAGE most bands were common but, nevertheless, each isolate was unique in the sense that they differed from one another in one or more bands. The marked heterogeneity of patterns observed when strains of M. ovipneumoniae are compared by BRENDA, together with the stability of such patterns over many generations, will enable this approach to be used to study the epidemiology of individual strains of M. ovipneumoniae within a flock.
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PMID:Comparison of Mycoplasma ovipneumoniae isolates using bacterial restriction endonuclease DNA analysis and SDS-PAGE. 300 24

The HsaI restriction enzyme from the embryos of human, Homo sapiens, has been isolated with both the tissue extract and nuclear extract. It proves to be an unusual enzyme, clearly related functionally to Type II endonuclease. HsaI seems to be an isoschizomer of EcoRI, but it has a distinctive property of elution, differing from EcoRI. Upon SDS-polyacrylamide gel electrophoresis, the enzyme preparation showed Coomassie blue staining bands, having the molecular weight of 65,000 and 22,000 daltons in size, respectively.
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PMID:HsaI: a restriction enzyme from human being. 303 22

OmpC and OmpF are major outer membrane proteins and although they are homologous proteins, they function differently in several respects. As an approach to elucidate the submolecular structures that determine their differences, we have constructed a series of ompC-ompF chimeric genes by in vivo homologous recombination between these two genes, which are adjacent on a plasmid. The recombination sites in the chimeric genes were localized by means of restriction endonuclease analysis and nucleotide sequence determination. Most of the chimeric gene products were accumulated in the outer membrane. One of the chimeric gene products, with a fusion site in a central region between the OmpC and OmpF proteins, was normally expressed but not accumulated in the outer membrane. The trimeric structures of some of the chimeric gene products appeared to be extremely unstable in a SDS solution. From these results, domains contributing to the formation of specific structures in which the OmpC and OmpF proteins differ were identified. Bacterial cells possessing the chimeric gene products were also investigated as to their sensitivity to phages that require either OmpC or OmpF as a receptor component. With the aid of the chimeric gene products, the immunogenic determinants for three anti-OmpC monoclonal antibodies were found to be localized at different portions of the OmpC polypeptide: the N-terminal, central and C-terminal portions, respectively.
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PMID:Construction of a series of ompC-ompF chimeric genes by in vivo homologous recombination in Escherichia coli and characterization of their translational products. 303 92

The gene expression of nine phages of the T7 group was compared after infection of Escherichia coli B(P1). With the exception of phage 13a which grew normally, all of them infected E. coli B(P1) abortively. Differences were found in the efficiency of host killing which ranged from 100% for phage 13a to 37% for phage A1122. Infection by T7 prevented colony formation by about 70% of the cells but they showed filamentous growth until about 2 h after infection. It was shown by SDS-polyacrylamide gel electrophoresis and autoradiography of [35S]methionine-labelled phage-coded proteins that all phages except for 13a showed measurable expression only of the early genes. No correlation was observed between killing capacity and the pattern of gene expression, and the ability to hydrolyse S-adenosyl-methionine (SAM, a cofactor for the P1 restriction endonuclease) by means of a phage-coded SAMase. Mixed infection of E. coli B(P1) with 13a and T7 yielded mixed progeny indistinguishable from that observed after mixed infection of the normal host E. coli B. Genetic crosses with amber mutants of 13a and T7 showed that the 13a marker opo+ (overcomes P one), required for growth on B(P1), is located in the early region, to the left of gene 1 (RNA polymerase gene).
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PMID:Inhibition of gene expression of T7-related phages by prophage P1. 304 52

Monoclonal antibodies against EcoRII endonuclease were obtained after immunization of two BALB/c mice with a homogeneous enzyme prepared by conventional methods. IgG from ascitic fluid was purified and coupled to CNBr-activated Sepharose 4B to give a specific column used to isolate EcoRII endonuclease. The isolated EcoRII endonuclease produced a single band during SDS gel electrophoresis.
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PMID:[Purification of restriction endonuclease EcoRII using monoclonal antibodies]. 306 Jan 97


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