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

A preparation of serially passaged simian virus 40 (SV40) DNA, in which at least 66% of the molecules contain covalently linked cellular DNA sequences, was digested to completion with the Hemophilus influenzae restriction endonuclease. Polyacrylamide gel electrophoresis of the digest showed that the majority of the cleavage products migrated as nine classes of fragments, each class defined by a particular molecular weight. These classes of fragments differ in molecular weight from the fragments produced by the action of the same enzyme on plaque-purified virus DNA. Three classes of fragments were present in less than equimolar amounts relative to the original DNA. The remaining six classes of fragments each contain more than one fragment per original DNA molecule. DNA-DNA hybridization analysis (using the filter method) of the isolated cleavage products demonstrated the presence of highly reiterated cell DNA sequences in two of the nine classes of fragments. A third class of fragments hybridized with high efficiency only to serially passaged SV40 DNA; the level of hybridization to plaque-purified virus DNA was low and there was essentially no hybridization with cell DNA immobilized on filters. It is suggested that this class of fragments contains unique host sequences. It was estimated that at least 27% of the sequences in the substituted SV40 DNA molecules studied are host sequences. The majority of these are probably of the nonreiterated type.
 ...
PMID:Acquisition of sequences homologous to host DNA by closed circular simian virus 40 DNA. 3. Host sequences. 435 51

Preparations of DNA from 12 Chlamydia psittaci isolates and one Chlamydia trachomatis strain were compared by restriction endonuclease analysis. Polyacrylamide gel electrophoresis, followed by silver staining, resulted in optimal resolution of fragments generated by digestion. By this technique, four distinct electropherotypes were demonstrated when ovine abortion, ovine arthritis, and avian and Cal10 strains of C. psittaci were examined. Minor profile differences allowed the discrimination of avian isolates derived from psittacine and columbiforme species, and the Cal10 DNA electropherotype was shown to have features in common with these profiles. However, there were no detectable differences in the DNA patterns of eight ovine abortion isolates.
 ...
PMID:Comparison of Chlamydia psittaci isolates by DNA restriction endonuclease analysis. 608 26

An endodeoxyribonuclease has been purified from nuclei of bovine small intestinal mucosa to a homogeneous state by a procedure involving affinity chromatography on heparin-agarose. The endonuclease, which was found to be bound to chromatin, has a pH optimum of 5.4. It requires Mn2+ or Co2+ for activity and its maximum activity with Mg2+ is about 80% of that with Mn2+. Its activity is strongly inhibited by sulfhydryl-blocking agents, and by ethidium bromide. The enzyme does not attack RNA and is inhibited by it. Its isoelectric point is 8.5 +/- 0.1, and its molecular weight is 49,000 +/- 3,000, determined by sucrose gradient sedimentation and gel filtration on Sephadex G-100. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate indicated that the enzyme is composed of two nonidentical subunits with molecular weights of 30,000 and 23,000. The enzyme catalyzes the endonucleolytic cleavage of circular duplex ColE1 DNA via single strand scissions from the initial stage of degradation. The average size of the limit products of native phage T7 or ColE1 DNA is about 2,000 to 1,500 base pairs, estimated by neutral sucrose gradient sedimentation or agarose gel electrophoresis. The enzyme degrades denatured DNA about 20 times faster than native DNA. The products contain 5'-phosphoryl and 3'-hydroxyl termini, and all four deoxymononucleotides are present in almost equal amounts at the 5'-termini.
 ...
PMID:Purification and properties of an endodeoxyribonuclease from nuclei of bovine small intestinal mucosa. 625 82

A new human adenovirus has been isolated from patients with keratoconjunctivitis and/or genital infection since 1976. This adenovirus, designed candidate adenovirus 37 (Ad 37) is serologically distinct but related to Ad 10, 13, 19, and 30 (see the accompanying paper by de Jong et al). SDS-Polyacrylamide gel electrophoresis of Ad 37 virion polypeptides showed that this adenovirus is a member of subgroup D. DNA restriction endonuclease analysis of DNA from Ad 37 and related serotypes belonging to subgroup D showed that Ad 37 is a new genome type belonging to subgroup D but clearly distinct from the 20 serotypes classified into this subgroup.
 ...
PMID:Characterization of candidate adenovirus 37 by SDS-polyacrylamide gel electrophoresis of virion polypeptides and DNA restriction site mapping. 626 86

The DNAs from bacteriophages Hh-1 and Hh-3 that infect Halobacterium halobium were characterized. Both phages contain linear double-stranded DNA and show no relatedness based on restriction endonuclease fragment patterns. Hh-1 DNA has 67.05% guanine plus cytosine (G+C) and a molecular weight of 24.6 X 10(6), whereas Hh-3 DNA has 62.15% G+C and a molecular weight of 19.4 X 10(6). Polyacrylamide gel electrophoresis indicated that the major proteins of the two phages are of different molecular weights.
 ...
PMID:Bacteriophages of Halobacterium halobium: virion DNAs and proteins. 688 22

Polymerase chain reaction amplification and BstNI endonuclease digestion were performed on DNA isolated from cell lines that were either homozygous (SW480, A549) or heterozygous (Calu 1, SK-LU-1, A427) for K-ras codon 12 mutations. Polyacrylamide gel electrophoresis showed that both mutant and wildtype (WT) bands were present in Calu-1, SK-LU-1, and A427 cell DNA; only the mutant bands were observed with SW480 and A549 DNA. The percentages of mutant and WT fragments were measured using capillary electrophoresis (CE). Integration of mutant and WT peaks showed that the percentages of mutant alleles in Calu-1, SK-LU-1, and A427 cell lines were 73, 84, and 72, respectively. The sensitivity of the original BstNI assay for K-ras codon 12 in conjunction with analysis by CE was also tested by a series of titration experiments using one- and two-stage amplification-BstNI digestion protocols. CE was used to generate a calibration curve. The mutant allele was detected and the quantity was measured in the 1:100 and 1:10,000 dilutions in the one- and two-stage analysis, respectively. Four human lung adenocarcinomas were also analyzed. Two of these were homozygous normal, whereas the other two contained 63 and 32% codon 12 mutant alleles. These results showed that CE can separate and quantitate BstNI fragments containing K-ras codon 12 mutations. The high sensitivity and quantitative features of CE should enable detection and quantitation of mutant K-ras alleles in premalignant lung lesions, as well as exfoliated cells collected by cytology from persons at risk for lung cancer.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Detection and quantitation of mutant K-ras codon 12 restriction fragments by capillary electrophoresis. 771 62

Polyacrylamide gel electrophoresis and agarose gel electrophoresis were used to resolve restriction endonuclease digests of 20 Australian Isolates of Leptospira interrogans cultured from urine samples of cattle with agalactia and abortion. The restriction endonuclease profiles of 19 isolates closely matched the profiles of L interrogans serovar hardjo subtype hardjobovis reference strains. The remaining isolate had a different restriction profile from subtype hardjobovis and subtype hardjoprajitno reference strains and was serologically identified as serovar pomona. Silver staining of polyacrylamide gels gave enhanced resolution of restriction fragments compared with the traditional method of ethidium bromide staining of agarose gels.
 ...
PMID:Restriction-endonuclease analysis of Australian isolates of Leptospira interrogans serovar hardjo from cattle with agalactia and abortion. 847 65

Pancreatic adenocarcinoma involves activation of the Ki-ras oncogene, inactivation of the p53 tumor suppressor gene, and dysregulation of growth factors and perhaps metastasis genes. Ki-ras oncogene point mutations are known to be involved in pancreatic oncogenesis. The p53 tumor suppressor gene product plays a critical role in cell cycle regulation and also functions as a nuclear transcription factor. Point mutations in the p53 gene have been observed in a variety of malignancies. We determined the frequency of p53 protein overexpression and p53 point mutations in the conserved and nonconserved domains in pancreatic cancers as well as the coincidence of Ki-ras mutation in pancreatic ductal adenocarcinoma. Genomic DNA was isolated from 20 frozen pancreatic adenocarcinomas (14 primary, six metastases) along with six specimens of control pancreatic tissue and screened by single-strand conformation polymorphism (SSCP) analysis followed by direct genomic sequencing of SSCP variants. SSCP analysis was accomplished by incorporating 32P-dCTP in 12 separate polymerase chain (PCR) amplifications covering the p53 coding exons 2-11. All mobility shifts on SSCP were subjected to direct genomic sequencing by the modified dideoxy method. Immunoperoxidase (IP) staining was also done with a p53 monoclonal antibody. Ki-ras codon 12 mutational analysis was accomplished by incorporating 32P-dCTP by polymerase chain reaction amplification utilizing mismatched primers, which create a BstN1 restriction endonuclease site spanning codon 12; the products were digested by BstN1. Polyacrylamide gel electrophoresis allowed distinction between wild-type and mutant Ki-ras. p53 mutations were found in 5 of 20 pancreatic cancers (three of 14 primary tumors, two of six metastatic tumors). Point mutations were observed in three of 14 primary tumors, and one of six metastases, while a 2-base pair duplication resulting in a premature stop codon in exon 5 was found in one metastatic tumor. Point mutations were noted in conserved domains (exons 4, 5, 8) and in the nonconserved domain (exon 10). IP staining revealed that eight of 14 of the primary tumors and two of six metastases exhibited moderate to strong nuclear staining (> 30%), while no nuclear staining was evident in the controls. Ki-ras codon 12 mutations were found in 14 of 20 (70%) pancreatic cancers (nine of 14 primary tumors, five of six metastatic tumors) and none of the six controls. Fifty percent of the primary pancreatic tumors demonstrated moderate to strong nuclear staining. Extensive genetic analysis demonstrated mutations in 30% of the pancreatic cancers. One cancer had a nonsense mutation not detected by IP. Seven of 19 (37%) pancreatic cancers exhibited both Ki-ras point mutation and p53 protein overexpression or mutation. Both genetic analysis and IP are required to characterize all p53 mutations in pancreatic cancer. Ki-ras codon 12 mutations and p53 protein overexpression are important steps in pancreatic oncogenesis.
 ...
PMID:Ki-ras and p53 mutations in pancreatic ductal adenocarcinoma. 892 12

In animals, the PABC domain from poly (A)-binding protein recruits proteins containing a specific interacting motif (PAM-2) to the mRNP complex. These proteins include Paip1, Paip2, and eukaryotic release factor 3 (eRF3), all of which regulate PABP function in translation. The following reports the solution structure of PABC from Triticum avestium (wheat) poly (A)-binding protein determined by NMR spectroscopy. Wheat PABC (wPABC) is an alpha-helical protein domain, which displays a fold highly similar to the human PABC domain and contains a PAM-2 peptide binding site. Through a bioinformatics search, several plant proteins containing a PAM-2 site were identified including the early response to dehydration protein (ERD-15), which was previously shown to regulate PABP-dependent translation. The plant PAM-2 proteins contain a variety of conserved sequences including a PABP-interacting 1 motif (PAM-1), RNA binding domains, an SMR endonuclease domain, and a poly (A)-nuclease regulatory domain, all of which suggest a function in either translation or mRNA metabolism. The proteins identified are well conserved throughout plant species but have no sequence homologues in metazoans. We show that wPABC binds to the plant PAM-2 motif with high affinity through a conserved mechanism. Overall, our results suggest that plant species have evolved a distinct regulatory mechanism involving novel PABP binding partners.
 ...
PMID:Solution structure of the PABC domain from wheat poly (A)-binding protein: an insight into RNA metabolic and translational control in plants. 1735 48

Thirteen isolates of egg drop syndrome (EDS) virus were compared by restriction endonuclease analysis of the virus DNA. One virus, an Australian chicken isolate, was distinguished from the others using the endonucleases EcoRl, BamUl, Kpnl, Hindlll, Pstl and Pvull, all of which recognise six base pair DNA sequences. Polyacrylamide gel restriction fragment patterns generated by Haelll, Hhall and TaqI, which recognise four base pairs, allowed further differentiation of the virus isolates. Nine chicken viruses isolated in the United Kingdom and Belgium in the period 1976 to 1987 were identical and could be distinguished from three United Kingdom duck isolates. The Australian isolate, in addition to possessing a DNA deletion (0.4 kbp) at one end of the genome (32.6 kbp) also differed from the European isolates at base sequence level. Genome maps for EcoRl, BamHl, Kpnl and Pstl are reported for the 127 isolate of EDS virus.
 ...
PMID:Differentiation of egg drop syndrome virus isolates by restriction endonuclease analysis of virus DNA. 1876 51


<< Previous 1 2 3 4 Next >>