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

---

Query: EC:3.1.30.2 (endonuclease)
18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the Mediterranean area, 50% of the beta thalassaemia mutations abolish or create a restriction endonuclease site in the beta globin gene. This study describes a new procedure for prenatal detection of these beta thalassaemia defects based on the direct visualisation, on an ethidium bromide stained polyacrylamide gel, of the discrete DNA fragments produced by restriction endonuclease digestion of fetal DNA, enzymatically amplified using the DNA polymerase from the thermophilus bacterium Thermus aquaticus. We applied this procedure to the Sardinian population to detect the nonsense mutation at codon 39 and the frameshift at codon 6 of the beta globin gene; these are the most frequent beta thalassaemia mutations in this population, accounting for 95% and 2.2% of the beta thalassaemia chromosomes. The main advantages of this procedure are simplicity (no radioactivity), sensitivity (0.2 microgram of DNA), and rapidity (12 hours). The very small amount of fetal material required makes amniotic fluid cell culture unnecessary and may decrease the fetal loss rate associated with trophoblast sampling. By circumventing the use of radioactive and non-radioactive probes, the spread of this technology to the high risk areas will be facilitated.
...
PMID:Prenatal diagnosis of beta thalassaemia based on restriction endonuclease analysis of amplified fetal DNA. 273 98

Sixteen methicillin-resistant Staphylococcus aureus (MRSA) isolates, from a single nosocomial outbreak, were tested for molecular and phenotypic relationships. Two of the 16 outbreak strains were gentamicin resistant (Gmr) and the plasmids that they carried were characterised by reverse field electrophoresis, restriction endonuclease analysis and gene hybridisation. The gentamicin-resistant (Gmr) strains harboured two plasmids, a Gmr plasmid of 36.5 kb and a cryptic plasmid of 25.4 kb, whereas the other 14 isolates contained only the cryptic plasmid. Gentamicin resistance was encoded by a 2.5-kb HindIII fragment of the 32.8-kb plasmid and is similar to the 2.5-kb HindIII fragment also described for S. aureus Gmr plasmids from Australia and the USA. The Gmr plasmid was non-conjugal and was cured by ethidium bromide at a frequency of 4%. Two MRSA strains isolated subsequently from the same hospital were also Gmr and had identical plasmid and restriction endonuclease profiles to the two Gmr strains studied initially. Two other S. aureus isolates from the original carrier detected in this study and from his son were methicillin and gentamicin susceptible and had novel profiles. Since large plasmids show anomalous migration in agarose gels, more definitive analyses than simple plasmid identification should be considered when studying nosocomial outbreaks.
...
PMID:Strategies for molecular characterisation of methicillin- and gentamicin-resistant Staphylococcus aureus in a Canadian nosocomial outbreak. 277 93

We have used endonuclease treatment in situ, followed by Giemsa or ethidium bromide staining, for mapping repetitive sequences on the chromosomes of the flesh fly Sarcophaga bullata and thus for studying extrachromosomal DNA granules in this species. All three restriction enzymes employed (HaeIII, A1uI and HindIII) show the same cytological effects, except for a single interstitial band. In both polytene and mitotic chromosomes, chromatin resistant to these endonucleases presumably includes at least three endonucleases presumably includes at least three previously unrecognized buoyant density satellites (1.663, 1.670 and 1.692 g ml-1 in neutral CsCl), and is predominantly localized in the pericentric regions of all five autosomes. Mitotic treated chromosomes show that the entire rod-shaped X chromosome, but no part of the dot-like Y chromosome, consists of endonuclease-resistant chromatin. The most unusual heterochromatic component of polytene nuclei in this species, the 'extrachromosomal DNA granules', are also entirely resistant to digestion with endonucleases. We think that these DNA granules represent dispersed X chromatin and not, as previously assumed, extruded autosomal heterochromatin.
...
PMID:Characterization and origin of extrachromosomal DNA granules in Sarcophaga bullata. 283 6

A new method for obtaining the recombinant DNA based on heteroduplex-initiated site-directed insertion of alien nucleotide sequences is proposed. To generate a single-stranded region, plasmid DNA was nicked with restriction endonuclease in the presence of ethidium bromide with subsequent exonuclease III controlled digestion. The inserted DNA sequences flanked by nucleotide sequences complementary to single-stranded region were annealed with plasmid DNA and E. coli cells were transformed by the resulting heteroduplex molecules. The presented data show the possibility to insert as many as 200 nucleotides. The yield of recombinant DNA varied from 16 to 0.7% as the number of nucleotides inserted correspondingly varied from 15 to 200. The site of insertion does not depend crucially on the localization of the restriction site used.
...
PMID:[Introduction of new DNA sequences into previously selected regions of a plasmid genome by means of the formation of heteroduplexes]. 283 23

Methicillin- and gentamicin-resistant Staphylococcus aureus (MGRSA) strains isolated from Dublin Hospitals were classified into two groups (phenotypes). Phenotype-I strains expressed high level resistance to gentamicin and were susceptible to fusidic acid; strains resistant to tetracycline harboured a 3 X 10(6)-mol. wt plasmid. Strains in phenotype II usually expressed low level resistance to gentamicin, were resistant to fusidic acid and often harboured a (22-24) X 10(6)-mol. wt plasmid that specified resistance to ethidium bromide, tetracycline, kanamycin, neomycin and trimethoprim, or to combinations of these markers. A few phenotype-II strains expressed higher levels of resistance to gentamicin and other aminoglycosides. All MGRSA strains carried a 21 X 10(6)-mol. wt plasmid conferring resistance to penicillin, ethidium bromide, cadmium and mercury. Gentamicin resistance was invariably chromosomal and all strains carried chromosomal resistance to methicillin, erythromycin, streptomycin and spectinomycin. Several methicillin-resistant S. aureus (MRSA) strains isolated before the emergence of gentamicin resistance harboured a 21 X 10(6)-mol. wt penicillinase plasmid with the same restriction endonuclease profile as that from some MGRSA strains. Some MRSA strains carried other plasmids related to those found in MGRSA strains.
...
PMID:Susceptibility to antimicrobial agents and analysis of plasmids in gentamicin- and methicillin-resistant Staphylococcus aureus from Dublin hospitals. 299 75

The replicative form (RF) of spiroplasma virus 4 (SpV4) has been purified from infected cells of Spiroplasma melliferum strain G1 by alkaline lysis followed by low melting point agarose gel electrophoresis. A partial restriction map has been established. The circular RF was linearized by cutting at the unique ClaI restriction site and has been cloned in Escherichia coli HB101 using the plasmid pBR328 as a vector. The recombinant plasmid was purified by equilibrium centrifugation in ethidium bromide-cesium chloride gradient. After ClaI endonuclease digestion, the inserted SpV4 RF DNA was recovered by low melting point agarose gel electrophoresis and was recircularized by ligation. The cloned SpV4 RF DNA was demonstrated to be infectious by transfection.
...
PMID:The spiroplasma virus 4 replicative form cloned in Escherichia coli transfects spiroplasmas. 301 May 60

A 48-year-old female had primary herpetic gingivostomatitis, followed by recurrent intraoral herpes simplex virus (HSV) disease; HSV isolates were obtained from the swabs of primary and recurrent lesions; restriction endonuclease cleavage analysis of the viral DNAs extracted from Vero cells infected with the HSV isolates according to the method of Hirt was carried out. The viral DNAs were cleaved by restriction endonucleases such as BamHI, KpnI and SalI and resolved by agarose gel electrophoresis, followed by staining with ethidium bromide. Consequently, their cleavage patterns were very similar to one another and were identified as HSV type 1. From these findings, it can be concluded that primary and recurrent lesions of this case are caused by the same virus.
...
PMID:Recurrent intraoral herpes simplex virus infection. 301 4

Campylobacter jejuni 3H40 and 4B20 harbored 59-kilobase (kb) self-transmissible plasmids encoding resistance to kanamycin and tetracycline. Although the two antibiotic resistances were more frequently inherited together, some transconjugants and ethidium bromide segregants which were resistant to only one of these antibiotics were recovered. The kanamycin-susceptible, tetracycline-resistant segregants carried plasmids 4 kb smaller than the 59-kb plasmids of their parents, whereas the kanamycin-resistant, tetracycline-susceptible segregants contained no detectable plasmid DNA. Restriction endonuclease maps of deleted forms of the 59-kb plasmids revealed that deletions and rearrangements of 4-kb lengths of DNA were associated with loss of kanamycin resistance. Translocation of the kanamycin resistance determinant between plasmid and chromosomal DNA was demonstrated. Such phenomena have not been previously described in C. jejuni spp. and are consistent with the interpretation that the kanamycin resistance determinant is encoded by a translocatable element.
...
PMID:Genetic studies of kanamycin resistance in Campylobacter jejuni. 302 Oct 49

Whole-cell DNA in Naegleria spp. and two related genera was examined by restriction endonuclease digestion and fractionation of the fragments by agarose gel electrophoresis. Visual inspection of ethidium bromide-stained gels shows differences in banding pattern between N. fowleri, N. lovaniensis, N. gruberi, N. jadini, N. australiensis, Didasculus thorntoni and Willaertia magna, and between the two subspecies of N. australiensis. Even between strains belonging to the same species differences could be observed. Significant differences were seen between strains of N. fowleri according to the continent of origin, and a hypothesis on the ancestry and the dispersal of N. fowleri was deduced from it. A N. fowleri strain isolated from one of the very few cured human infections showed the most distinct pattern within the species. The considerable variation detected with serological and biochemical techniques between strains of N. australiensis as well as between strains of N. gruberi, was confirmed in the analysis of their whole-cell DNA. With this technique the existence of N. jadini, D. thorntoni, W. magna and two Naegleria strains as separate systematic entities is substantiated.
...
PMID:Characterization of Naegleria species by restriction endonuclease digestion of whole-cell DNA. 303 68

Gentamicin-resistant Staphylococcus aureus and Staphylococcus epidermidis strains which were isolated from infants with staphylococcal bacteremia were analyzed for the presence of self-transmissible gentamicin-resistance (Gmr) plasmids. Conjugative GMr plasmids of approximately 43.8-63 kilobases (kb) were found in all S. aureus strains. Inter- and intra-species transfer of Gmr plasmids by conjugation was observed from S. aureus to S. aureus and to S. epidermidis recipient strains. However, neither inter- nor intra-species transfer of gentamicin resistance by conjugation was observed with nine out of nine S. epidermidis donor strains which were mated with either S. epidermidis or S. aureus recipient strains. These conjugative Gmr plasmids were unable to comobilize a smaller (15-kb) plasmid present in all but two S. aureus clinical isolates. Many of the conjugative Gmr plasmids also carried genetic determinants for kanamycin, tobramycin, neomycin, and ethidium bromide resistance, and for beta-lactamase synthesis. EcoRI restriction endonuclease digests of the S. aureus Gmr conjugative plasmids revealed three different digestion patterns. Four EcoRI restriction endonuclease digestion fragments of 15, 11.4, 6.3, and 4.6 kb in size were common to all plasmids. These plasmids and conjugative Gmr staphylococcal plasmids from other geographical regions shared restriction digestion fragments of similar molecular weights. DNA hybridization with biotinylated S. aureus plasmid pIZ7814 DNA revealed a high degree of homology among these plasmids. A 50.9-kb plasmid from one of the nonconjugative S. epidermidis clinical isolates showed homology with the probe DNA but lacked a portion of a 6.3-kb fragment which was present in all conjugative plasmids and believed to carry much genetic information for conjugation.
...
PMID:Molecular analyses of conjugative, gentamicin-resistance plasmids from staphylococcal clinical isolates. 321 9


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---